A Couple Basic Electrical Questions

[Steve83]

You're not "draining power from the coil" - you're just pulling a little more current through the R/Gn wire. As long as that wire doesn't get hot, then it's supplying enough for both. It'll never affect the coil, no matter what.

 

[Jeff10]

Hi Steve,

You're not "draining power from the coil" - you're just pulling a little more current through the R/Gn wire. As long as that wire doesn't get hot, then it's supplying enough for both. It'll never affect the coil, no matter what.

Sorry for the poor choice of words. I understand what you're saying, too, about drawing too much current through the wire.

Although not ideal, I could always wire the control side of a small relay through that same wire... after confirming that the small relay draws less current than the propane solenoid.

Thanks

Jeff

 

[67686977]

What is wrong with just using the fuse panel? If not finding a keyed source available, you can always use a vacuum switch on an always hot wire. Vacuum switchs which cut off the power to the solenoid when the engine isn't turning over, were very common on lp systems in the 80s. Plus you will have a fused wire going to your shutoff while leaving your ignition system alone.

 

[Jeff10]

Hey,

What is wrong with just using the fuse panel? If not finding a keyed source available, you can always use a vacuum switch on an always hot wire. Vacuum switchs which cut off the power to the solenoid when the engine isn't turning over, were very common on lp systems in the 80s. Plus you will have a fused wire going to your shutoff while leaving your ignition system alone.

Both of those are good points.

I'll take a look at the fuse panel to see what's available.

I also like the vacuum switch idea. The only downside is that there would be a slight delay in operation compared to the power from the keyed source; but, I don't see that as being a problem.

Thanks for the suggestions.

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.

(Viperwolf and Paul ... This addresses your posts, too.)

I was finally getting around to installing a MSD solid state coil today. I intended to install it several years ago, and just now see the benefit with the propane.

The initial setup was with the two wires from the resistor connection from the harness in the engine compartment and the wire from the ignition switch wire to one side of the resistor. The other side of the resistor was wired to the + side of the solid state coil. The motor cranked and started; but, after about 30 seconds the engine wouldn't run... it was missing and wouldn't idle.

I switched back to the conventional coil. The motor started and ran fine. (I may have the timing a little far advanced now; but, the motor idled pretty well.)

So... I went back and removed the two wires to the one side of the ballast resistor. I connected the wire from the ignition switch to the balast resistor, leaving the wire from the connection in the engine bay unconnected. The motor would not start. (It may be worth mentioning that the moment I turned the key from the start position to the normal running position, there was ignition for just a short time, although the motor didn't start.)

I then removed the wire from the ignition switch and connect the wire from the harness in the engine bay. The motor started and idled well.

I then switched coils with only the engine harness wire connected to the ballast resistor. The motor idled for about 10 minutes with no problem.

So, it appears that the conventional coil is tolerant of the way the ballast resistor was wired previousl; but, the solid state coil won't run with the wire from the ignition switch wired to it.

I don't know the reason why one of the previous owners would have wired both wires to the ballast resistor. I was doing my best to get under the dash and see which terminal on the ignition switch was wired to the ballast resistor; but, I couldn't tell. I think my only option if that's needed is to remove the switch. (Or, is there a switch assembly that can be removed from the switch so that the wiring can be looked at below the dash?)

Thanks for any thoughts.

Jeff

 

[Steve83]

...is there a switch assembly that can be removed from the switch...?

I don't understand this question. %)

 

[Jeff10]

Hi Steve,

I don't understand this question. %)

You're right... that wasn't worded the way it should have been.

I'm not sure this will come out any better; but, I'll give it a shot.

I am thinking that I have seen switches where the keyed portion of the switch is mechanical and a phenolic type block with all of the electrical contacts is attached to the back of the mechanical switch. Using the key to turn the mechanical switch causes rotation against the electrical contacts in the attached electrical housing.

I should probably just ask if it's necessary to remove the ignition switch to gain access to the ignition switch so that I can tell exactly how it is wired.

Sorry for the confusion.

Jeff

 

[70_Steve]

I should probably just ask if it's necessary to remove the ignition switch to gain access to the ignition switch so that I can tell exactly how it is wired.

Different Steve...

All depends on how flexible you are. It's possible to stick your head under the dash and see the wiring. But for me (6"5" & 250lb) it's not the easiest thing to do, especially if I have to be under there longer than about 2 minutes.

I spliced into the wires on the back of the ignition switch to get the Start and Run connections for my EFI. I did remove the switch from the dash and let it hang underneath to do the splices.

 

[Jeff10]

Hi Steve,

Different Steve...

All depends on how flexible you are. It's possible to stick your head under the dash and see the wiring. But for me (6"5" & 250lb) it's not the easiest thing to do, especially if I have to be under there longer than about 2 minutes.

I spliced into the wires on the back of the ignition switch to get the Start and Run connections for my EFI. I did remove the switch from the dash and let it hang underneath to do the splices.

Thanks

I'm not quite as big as you... but, it's pretty tough for me, too, to spend much time there. (Add to it less than perfect eyesight and it's a challenge.)

I will look in the manual that I have on CD regarding removing the switch from the dash. Do you have any tricks you learned when you removed your switch?

Thanks again.

Jeff

 

[70_Steve]

I will look in the manual that I have on CD regarding removing the switch from the dash. Do you have any tricks you learned when you removed your switch?

There's a Tech Article that shows a bit of what you need to remove the ignition switch.
http://classicbroncos.com/tech/early-bronco-ignition-switch-removal

Look at Figure 7. It shows all the pieces so you can get an idea of how the switch is to be removed and installed. Removing the tumbler can take a bit of jiggling, but should come right out. The trick is in getting one hand behind the dash with the other in front. Push the front bezel and the switch towards each other and twist.

The couple times I've done this, it seems like I can remove the switch from the dash with no problems. But getting it back together takes me 15-20 minutes, a couple breaks to calm down, and a few choice expletives.

 

[DirtDonk]

That is the best way to actually get to play with things with the battery connected, but to just find out what the wires are connected to, you can unscrew the nut on the back stud of the ignition switch, remove any wire terminals from the stud (there only one from the factory, but yours might have more) and pull back on the black plastic part of the switch.
It's actually a formed plug/connector that pushes on and off.

Once you've pulled that off, you should be able to pull the wires down below the dash to give it a good look-see.

Paul

 

[Steve83]

This diagram shows the ig.sw. connectors in fair detail:



Click it again in the new window to supersize.

 

[Jeff10]

Hey Guys,

With only wire 16 connected to the ballast resistor from the connector in the engine bay, the Bronco ran great yesterday.

I'm more than a little curious about the additional connection... without know what one of the previous owners experienced, it's pretty much impossible to understand what he hoped to accomplish.

I put 40 or 50 miles on the Bronco yesterday around town and on the interstate... there were no problems that I encountered.

Thanks Steve83 for the link. That was really helpful when I was troubleshooting the problem initially.

Take Care

Jeff

 

[DirtDonk]

Did you ever get this sorted out Jeff? I know we've talked a lot since this was current, and if I'm not mistaken you've been running it around. But I wondered if you've been able to clean up all the wiring.

You said your ammeter was not working. Have you checked the wire at the gauge to make sure it's passing through the loop?

Anyway, I PM'd you to see if you had any current pictures of under the I could check out.

Thanks

Paul