A Couple Basic Electrical Questions

[DirtDonk]

Jeff, does the Red wire that goes into the cab and to the ignition switch look like it's been replaced all the way to the key? Or is it factory looking and Red w/green?
Reason I ask is that your drawing looks like the factory connector, where the "Red" wire would have been Red with a green stripe. Either all the way to the key, or with an isolated and insulated section of another color under the dash. I've seen Gray and Pink too, but mostly it's Red w/green.

That bit between the plug and the key would have been the factory resistor wire. So if it's intact, and the Red is really Red w/green, you probably don't even need that external ballast resistor.
Just thought I'd add another level of electrical cursedness to your plate!

Just mentioning that in case, during your wire tracing/detective work, you find that you have two resistors in the ignition circuit.
The Brown wire in your drawing would have come from the starter relay's "I" post and give the coil it's juice during start. Not only to make sure it has full 12v for easier starts, but to make sure it has ANY juice in case the ignition switch doesn't make it's connection during START too.

Be curious to hear what you find about that second wire on the chassis side of the ballast resistor.

How is it running now? With all of those added wires, has it been running fine? If not, it'd be a shame to put all the work into hooking up propane and other circuits only to have to track down gremlins still.

Good luck.

Paul

 

[DirtDonk]

I see no reason for it. It just limits the charge rate to the aux battery. I guess it could be protecting the isolator diodes from excess current if the aux battery was completely drained. But that would prevent you recharging it.

It was probably just their version of a fusible link that they knew wouldn't be on most installer's list of things-to-do when putting one of their isolators in.
Would also be easier for people to use and repair if defective.

If I remember it was a 50 amp breaker, which would be fitting for a small stock system. And while it may very well have been limiting current, it never kept a battery from charging.
Not the most efficient, but worked.

Paul

 

[DirtDonk]

Jeff10, does your ammeter work at all? It "shouldn't" from what I see in your diagram, but hey, you never know.

Paul

 

[Steve83]

What's the concern, out of curiosity?

Same reason I'd be concerned about a breaker between the main batt. & the rest of the vehicle. A battery can & should be able to put out ~800CA. What's the point of having a battery with that capacity if you're gonna limit it to only 50A? You might as well put in a UPS (wheel chair) battery as your aux since they can't put out more than ~50A anyway.

My aux.batt. is to help with my winch, which is what I suppose most people add an aux. for. But with a 50A breaker, you can only get 50A more than your main batt. plus your alt. can put out, so why go to all the trouble & expense of adding a ~90lb starting or deep-cycle battery? Those extra 50A would probably just go to pulling the extra weight of the battery system.

 

[DirtDonk]

Circuit breaker in this case has nothing to do with the battery's capacity to put out to a big load. It's not even on the same circuit as any item powered from it.
The only function of the wire that the CB is inline on is to carry the charge from the alternator to the battery. The Load Center is powered on it's own branch.

There's no doubt that if you were using this battery for winching, starting, or any other heavy use that the main cable was carrying, that little CB would be overwhelmed quickly. But it's strictly for cutting off the flow, should things get ugly between the Isolator and the battery.

For this particular circuit (at least the one on mine and, it appears, on the OP's), you could easily use a 10ga wire for the charging duties. Just like Ford did, but with a fusible link instead of a circuit-breaker. And winching/charging/starting doesn't blow those, or melt the wire, because that's not the wire that is used for those heavier duties.

Does that change anything?

Paul

 

[Steve83]

No.

There's 1 wire from the aux.batt. (+) to the truck. Everything that happens with that battery, happens via that wire. Charging AND discharging. Alternator pushing power in, and lights/stereo/winch taking power out. Everything. So if there's a 50A CB on that wire, then the battery is limited to 50A in either direction. Even if it's a fully-charged 1100CA battery, you'll never get more than 50A going in or out. No matter what size the wire is (as long as it can handle at least 50A). The CB (or fusible link or fuse) can't tell the difference between a wiring fault, an isolator fault, and a normal heavy load. That's why there's never any circuit protection between the battery & the starter, on any vehicle.

 

[DirtDonk]

Sorry for the side-jack Jeff. But since it's all about your Bronco anyway, I figured you wouldn't mind too much when you got back around to this.
But it's going to be one of my epic ramblings most likely too, so just ignore it if it doesn't pertain.
And you can ignore it too if you want Steve but I hope you'll read through it anyway.

Same reason I'd be concerned about a breaker between the main batt. & the rest of the vehicle. A battery can & should be able to put out ~800CA. What's the point of having a battery with that capacity if you're gonna limit it to only 50A?

No, it shouldn't put it's 800cca through the main harness. Which is what we're talking about here. ONLY the starter and battery cables (and winch, if present) get even remotely any of that on an EB.
In fact though, most vehicles ARE limited by some sort of protection between the battery and cabin. Including the Bronco. You know that of course, but for some reason I think you keep equating maximum battery output and re-charging capabilities with what flows through the main harness and into the fuse box and other stuff. When what we're talking about is only the amount of current that a (hopefully small!) alternator is capable of putting through a stock Bronco charge wire and low-rated isolator.
Two different parts of the system then. The main accessory loads, and the starter and winch) system.
On an EB, the main accessory load actually includes the charging loop, but at a whopping 10 gauges of wire, it's not really up to carrying a starter or a winch's or a battery's maximum current either.
But it could certainly handle that original 45 amps of charge current.

That protection, either by a fuse (many aftermarket harnesses) or mulitple fusible links (all EB's) is there to keep an unexpectedly excessive load from melting the 10ga charge wire. Right?
Could be the same on his with the CB.

Painless includes a 60 amp Maxi-Fuse in their kits.
Centech, AAW and others include a fusible link for their main harness protection. Not sure what their max capability is, or how long they take to blow, but they're there just like the Circuit-Breaker is.

The original alternator on the Broncos was 45 amps from the factory. Even aftermarket ones of the day were only up to 50, then 55 and even 65 amps.
The isolator he's using, if like many, is likely rated for only 50 or 60 amp max as well. Maybe less.

None of the big loads you're talking about even go through the charging circuit or the cabin wiring. Only time those big loads go through the charge wire is when you have a high-output alternator and larger charging cable that's been added as a bypass, AND the load is connected through that cabling before the battery.
Or a short-circuit...

We don't know what Jeff's got for an alternator yet of course, but apparently the charge and load are still passing through the original 10ga charge wire from the Bronco, through an amp-limited isolator, and then to both batteries.
Still making me think that the CB is not the limiting factor you say it is here.

It may not be the best way of protecting the circuit from the sound of it, but it doesn't seem to me to be this big choke-off either.
And haven't other members here mounted big HD circuit-breakers in their systems here many times over the years?

My aux.batt. is to help with my winch, which is what I suppose most people add an aux. for. But with a 50A breaker, you can only get 50A more than your main batt. plus your alt. can put out, so why go to all the trouble & expense of adding a ~90lb starting or deep-cycle battery? Those extra 50A would probably just go to pulling the extra weight of the battery system.

I hear 'ya. But I don't think at the moment he's got a winch on that battery. I didn't either. Only used it for radios and a refrigerator all those years. And it always kept my batteries charged.
But at the moment too, I'm "assuming" again that the wire between the isolator and aux battery is of smaller gauge than a normal battery cable.
Why? Because it's connected to a little tiny CB and that would be pretty awkward to do with most store-bought cables unless they had their ends cut off and custom crimped with likely hard-to-find little #6 holes on 4ga cable. ;D

And in your case, you have a larger alternator(?), with a larger charge wire(? assuming again!), to help even remotely keep up with the demands of a winch. And, you won't even consider using a battery isolator anyway, if I remember from previous discussions.
We don't know there's a winch or starter motor at the other end of the battery yet. But likely not.
Hopefully Jeff can clarify all that when he gets around to posting some pics and further descriptions, but if he's got a winch or other heavy load on the aux battery, he'd better also have a larger alternator, new charge wire and eliminate the isolator all-together.
Right?


It didn't look to me initially like the isolator had been wired correctly anyway. At least not to continue to use the ammeter anyway. Which is why I asked him about it.
But we can wait until he posts up those pics.
I just still don't see how the CB is as big an issue as you say. Sure, it's apparently the lowest common denominator. But the other items it's protecting (stock wires and isolator) are not likely rated at much above it's capability.

Paul

 

[Jeff10]

Hi Paul,

No problem providing more details.

I apologize that I have been a little tied up with the propane conversion. Once I actually start my vacation, I'll post more details.

A couple of quick notes:

1. I know that it probably isn't best practice; but, I have powered the coil of the propane solenoid from the + terminal on the coil. That was a recommendation of the kit supplier. He said that's the way he has done it in the past. It's a 1A coil, so the power draw is minimal. I have a relay mounted, and I intend to wire it to the coil when I am clear about the switched source. (I am still confused about that detail. Quite a bit of the wiring in the Bronco has been replaced so the wire colors are different.)

2. As indicated earlier, the tach is being powered by the + side of the coil. Since the addition of the power to the coil of the propane solenoid, the tach stops working after several minutes. (Just curious about that, although it won't be a big deal as the coil will eventually be powered from a different source. Is there a better source of power for the tach?)

3. Last year I replaced and rewired the back-up switch at the transmission (T18). There was no wiring, so I ended up just wiring the switch to the battery. Not a good idea if you're used to leaving the transmission in reverse. Any ideas of a better power source for the back-up switch?

4. I am going to address the breaker on the auxiliary battery when we get to Moab.

5. The ammeter does not work. I thought that it did last year; but, to be honest, I really can't remember. I will take a look at the correct wiring when we get to Moab. (Besides the information that I'll find when researching the wiring requirements, any advice here would be appreciated.)

Pictures and details of the propane install will be posted in a few days.

Thanks

Jeff

 

[DirtDonk]

One reason that most people say to resist using the positive side of the coil as a power source for other accessories (even a relay) is that any power taken away from the coil is not a good thing for your ignition performance.
Add to that the fact that this old wiring may not be perfectly up to snuff to begin with, and that the wire going to the coil is using reduced voltage (lowered by the ballast resistor) in the first place, you've just got a recipe for trouble. If not now, then at least down the road.

For your backup lights, the center post of your (supposedly?) stock ignition switch would be fine. Normally I like to keep extra loads off the already well worn ignition switch, but since it's such an intermittent load, it's probably not going to do any harm.
If you run larger/more powerful or more backup lamps however, then convert that power source to a relay and you're good to go.
The center post of the back of the switch is the ACC source. So it's stuff that's on when the key is in RUN as well as ACC.
Just like the backup lamps would have been wired originally in fact.

Paul

 

[TwoDalesDad]

Jeff thank you for the responce.... I used to watch the racers take off from Ensenada as a youngster.....I more or less grew up...between Hussongs..and papas&beers...and Estero Beach resort....my best in baja was 12 place...class 5-1600...builder/crew/ good times

 

[Steve83]

Jeff
Just ignore this if it doesn't make sense to you - Paul & I are getting hypertechnical (a really RARE event ;D), and most of what I'm posting here is just elaboration on what I said initially. Ultimately, I'm still saying "lose that CB."

Paul
There are a few people here that I try to ignore - you aren't among them. And any post that I take the time to reply to, I try to read at least twice to make sure I'm reading it correctly.

...through the main harness. Which is what we're talking about here.

Actually, we're just talking about the wiring between the batteries.

ONLY the starter and battery cables (and winch, if present) get even remotely any of that on an EB.

Maybe on a stock eB, but he said his has had a lot of wiring mods (repeated in post #28 end of paragraph #1), and (like all driven eBs) it's likely to have many more in the future. So even though that CB might not be a big issue today, it's likely going to become a big issue later. And it's not helping anything today, so there's no reason to keep it.

In fact though, most vehicles ARE limited by some sort of protection between the battery and cabin.

But that CB isn't between the batteries & the cabin; it's between the batteries. If it was between the main batt. & the rest of the truck, I probably wouldn't have mentioned it.

...I think you keep equating maximum battery output and re-charging capabilities with what flows through the main harness and into the fuse box and other stuff.

No, but I might equate the effectiveness of any mod to its adaptability to future mods. ;D

...low-rated isolator.

I didn't see where he said what the isolator's battery-to-battery capacity is. %) But I assume it's >50A, which would make the CB an unnecessary & counterproductive restriction.

Two different parts of the system then. The main accessory loads, and the starter and winch) system.

Right. So since the CB is only in the battery/starter/winch section, why do you keep talking about the rest of the truck? ?:?

That protection...is there to keep an unexpectedly excessive load from melting the 10ga charge wire. Right?

If you mean the stock fusible link from the starter relay to S201:



...then, based on my observations both on Frank's '75 & the threads I've read here, I'd say it's oversized and doesn't effectively protect anything. But yes: I think it was intended to protect the ammeter loop.

And that has nothing to do with the CB in question since the CB doesn't replace that fusible link, and isn't even on the same circuit.

Could be the same on his with the CB.

Not even remotely. A heavy load in the truck will still burn that fusible link, and NOT trip the CB since it will still draw from the main battery. That's why I still say the CB is completely unnecessary, and counterproductive for several reasons.

None of the big loads you're talking about even go through the charging circuit or the cabin wiring.

So why are you talking about the cabin wiring? Let's stick to the batteries.

And haven't other members here mounted big HD circuit-breakers in their systems here many times over the years?

A "big HD CB" would be an entirely different story. This is a "little LD CB".

But I don't think at the moment he's got a winch on that battery.

Do you think he never will? Do you think the CB is protecting anything on the truck right now? Do you think it ever will? I don't - that's why I mentioned it.

...a little tiny CB...

NOW you're getting it! ;D

And in your case, you have a larger alternator(?), with a larger charge wire(? assuming again!)...

Not that it's relevant, but no. I'm using a stock 130A 3G and the stock charge wire (used for both sizes of alt on '93-96 trucks).

...to help even remotely keep up with the demands of a winch.

I don't consider the alt. to be part of the winch system since even a big aftermarket alt. can't put out half what my winch needs. A small alt. would still recharge as many batteries as I could carry, and a big one wouldn't speed up the winch, or allow it to run longer. The aux.batt. is for the winch; the alt. is for the e-fans, power inverter, A/C, & all the other crazy electrical mods.

And, you won't even consider using a battery isolator anyway, if I remember from previous discussions.

I don't see how that's relevant to his CB, but yes, I've considered isolators. I decided that they're not cost-effective, reliable, or best-practice, so I'll never use or recommend one.

But I didn't suggest he get rid of the isolator - I'm only talking about the CB.

We don't know there's a winch or starter motor at the other end of the battery yet. But likely not.

"YET" being the operative word.

...he'd better also have a larger alternator, new charge wire and eliminate the isolator all-together. Right?

Depending on the aux.batt., the assumed winch, and how he wants his truck to work, he might keep the isolator, alt., & fusible link/charge wire until each one craps out, and then make changes.

But in no case does that CB benefit anything. In my experience, it's not even reliable enough to have there at all. I've seen too many develop high resistance, cause a voltage drop, overheat, fall apart, & short their unprotected post to ground.

I just still don't see how the CB is as big an issue as you say.

How big an issue did I say it was? ?:? I said:

...a breaker between the aux.batt. & the isolator - that shouldn't be there.

What's the point of having a battery with that capacity if you're gonna limit it to only 50A?

...the battery is limited to 50A in either direction.

 

[Jeff10]

Hi Guys,

I am taking this one step at a time.

Based upon what everyone has said, it appears that the two wires on the one terminal on the ballast resistor are redundant.

The older (original wire) appears to be the #16 red w/green stripe coming from a connector located in the engine compartment. I believe that the red wire is coming from the ignition switch, although I haven't been able to trace it down to that.

A couple of questions...

1. If it is working now, should I really try to eliminate one or the other?

2. If I should eliminate one, which one would be the best candidate?

3. For the control side of the propane relay, should I wire to one or the other? (If wires stay on the ballast resistor, it really won't make a difference, will it?)

Based upon the wiring diagram provided by Steve, it appears that the red wire with the green stripe from the connector would have originally gone to the stock resistor. Would the ballast resistor just been used to replace that section of the wiring? (In that case, perhaps the red wire on the same terminal on the ballast resistor is providing a signal of start/run to another function?)

Thanks for any input.

Jeff

 

[Steve83]

1. I don't see a need, as long as the wires are properly terminated & insulated.

...perhaps the red wire on the same terminal on the ballast resistor is providing a signal of start/run to another function...

Easy to check: with the engine running, disconnect one. If nothing changes, put it back & disconnect the other.

 

[Jeff10]

Hey TwoDalesDad,

Jeff.....please give us a run down on your propane setup....i am very interested in doing the same conversion....

Here's a link to a thread with some information on the propane conversion:

http://classicbroncos.com/forums/showthread.php?t=229470

I thought it might be better to start a separate thread so that I don't hijack this one more than I already have.

Thanks

Jeff

 

[Jeff10]

Hi Steve,

1. I don't see a need, as long as the wires are properly terminated & insulated.Easy to check: with the engine running, disconnect one. If nothing changes, put it back & disconnect the other.

Doing what you suggest isn't tough; but, I will need to rework the connector first. Both wires are crimped to the same connector.

This may be a stupid question; but, what is the downside to the present setup? We had the Bronco out on the trails yesterday with no ignition or fuel system problems. Will the extra load cause the coil to fail sooner, or is it just a matter of the coil possibly not receiving enough power? Don't get me wrong, I like to do things the right way. I guess I have learned in the past that fixing things until they're broken is something I'm pretty good at ... and right now the Bronco is running great.

(I plan on installing a solid state coil and contact-less points that I purchased two years ago... I'm just not sure that is necessary right now, though. That may make a difference in the wiring of the propane solenoid.)

Thanks again for your input.

Jeff

 

[Steve83]

...what is the downside to the present setup?

The only one I can think of is what I've already said about that breaker. Maybe VW or DD know some disadvantage to the resistor, but I'm not that familiar with these old ignition systems. Maybe they already mentioned it, so look back through their posts.

 

[DirtDonk]

Leave the ignition the way it is until such time as you either have time to track down each wire and it's condition, or decide to re-wire things.

If it was only the old stock wire, the disadvantage would be a double-resistor. The old wire IS a resistor wire, so does not need (nor would you want) an external ballast resistor.
However, the newer Red wire is probably a full 12 volts, so you're not losing too much as long as it's intact.

What may have happened in the past is that the original resistor wire either broke or melted, or otherwise failed in it's function. To keep the ignition happy the PO simply added a new 12v wire from the switch to an external ballast to keep the ignition coil and/or points happy.
That's the most likely scenario I can think of anyway, for the current setup.

I'd leave it as is then, until you're ready to just clean things up or change other components.
Like you said, it's working now.
When you do change your ignition to the stuff you were talking about, you'll just need to verify whether it needs the full 12 volts to operate (eliminate the ballast resistor in that case) or uses the more reduced 9-ish volts (leave the resistor in) to operate.

Paul

 

[DirtDonk]

Jeff
Just ignore this if it doesn't make sense to you - Paul & I are getting hypertechnical (a really RARE event ;D)...

Hey Steve. Sorry it took so long for me to get back to this.
Thanks for continuing to respond. And for keeping your sense of humor about it all too!

No sense in me trying to rehash everything again. So I'll just say that...
I'm right! ;D
Or you are. Oh well, you're right more often anyway, so we'll just leave it. I think I'm not doing a good job of describing what I think I'm seeing, and since you're not actually "wrong" with what you've said, I can't be "more right" anyway. Can I?

Bottom line Jeff. Might as well lose that circuit-breaker.
But I would say to get some kind of protection in the charging circuits if it's not there already.

And if you do still have a stock-type alternator and want your ammeter to work again, shout out and we'll walk you through a few changes to the connections that should help.
Most people prefer a voltmeter to an ammeter anyway. But I still like them, and in the case of a near-stock alternator output and if the ammeter is still in place, why not use it I say.

Paul

 

[Steve83]

...I'm right! ;D
Or you are. Oh well, you're right more often anyway, so we'll just leave it. I think I'm not doing a good job of describing what I think I'm seeing, and since you're not actually "wrong" with what you've said, I can't be "more right" anyway. Can I?

%) Uu-uu-uhuhu... ?:? I can't argue with that!

 

[Jeff10]

Hi Paul,

And if you do still have a stock-type alternator and want your ammeter to work again, shout out and we'll walk you through a few changes to the connections that should help.
Most people prefer a voltmeter to an ammeter anyway. But I still like them, and in the case of a near-stock alternator output and if the ammeter is still in place, why not use it I say.

Paul

I do believe the alternator is stock, although I don't know for certain. I would like to have an indication in the cab that the system is charging, so I think it would be good to troubleshoot.

In the case of the start/run signal I am more concerned about the propane coil. At the moment it is wired to the coil. I understand that I am draining some power from the coil; but, the ignition system is working well. Is the primary concern that the drain at steady state is a problem, or is it that the constant drain will cause a premature failure of the coil? In other words, is there a long term consequence to having it wired this way. (I'm not saying that I particularly like the way it is wired, it's more that I hate to make changes that might have other consequences until I really have time to troubleshoot everything.)

I feel bad taking up your weekend.... but, thank you.

Jeff