Brainstorming A Couple of Electrical Problems

[Jeff10]

Hi Guys,

I'll admit that I haven't worked through the issues I'm going to mention enough to justify posting them here... just thought someone might say something that makes sense with the troubleshooting.

I'm having two electrical issues right now that I'd really like to figure out once and for all. I'm not sure if they are connected in any way... but, I guess it's possible.

1. I have a 1-wire alternator that I bought from another member. I installed it before Moab last year, and it did great (after a little misunderstanding on my part about the wiring). A couple times since Moab I have noticed that the alternator doesn't appear to be charging. I have a voltmeter in the cab that show a little over 12 volts (even when I rev the motor up over 1,500 RPM). I have checked the voltage at the battery, it is about 12.5 volts. This has come and gone a couple of times, with nothing done that I know of to make the problem go away.

2. The dash lights are not working. (There's another thread where there have been some suggestions made about troubleshooting.) I have added grounds between the battery and the body, and between the motor and firewall. I have also exercised the rheostat. I haven't checked the other grounds that were suggested yet. (I'm thinking about replacing the light switch just to remove all doubt about the rheostat.)

Any thoughts? I don't want to say the wiring is a disaster; but, it is complicated with a dual battery setup (with an isolator), an air compressor and some other modifications. I could have messed something up; but, it has worked in the past.

Thanks,

Jeff

 

[Rustytruck]

When the rheostat burned out on my headlight switch I just soldered in a jumper on the rheostat to provide full voltage when the lights are on. I never needed the inside lights dimmed. That was over 25 years ago.

 

[September 1972]

The dash lights are grounded to the metal dash structure then from there the orphaned electrons have to go searching for the negative battery terminal which is on the engine block. Run a short wire from the neg battery to the fender bolt and see what happens.

 

[Jeff10]

Hi Guys,

Thanks for the input.

I did add grounds from the battery to the fender, and from the engine intake to the firewall.

I'll do a little more digging this morning.

Take Care,

Jeff

 

[Steve83]

1) It's possible that the VR is dying. What model of 1-wire alt is it - GM, Ford 3G, etc.? Some can be easily bypassed for diagnosis.

2) Find any ONE of the LB/R dimmed dash wires, and apply 12V to it. Regardless of key or light switch position, all the dimmed lights should come on full brightness. If they don't, they're either burned out or not grounded.

When you add grounds, don't just add them randomly. Start at the battery (-) cable, and make a continuous path, hitting as many metal objects as possible: core support, each fender, firewall, frame, engine... Make the firewall ground a pass-through bolt, and start another string inside the cab: firewall, dash, doors, t/g, top...

 

[73azbronco]

Take alternator into autozone let them run a test on it for free.

 

[Steve83]

That would be overpriced for what it's worth, just like everything else at the zone.

 

[chuck]

On that one wire there should be a small red wire the mounts under the battery cable. Sometimes the batt. cable does not fit into the red shield so does not tighten onto the small red wire and causes this kind of problem.

 

[Jeff10]

Hi Steve,

Thanks for the input. We've been traveling for the last couple of day.
Finally got unpacked this afternoon.

1) It's possible that the VR is dying. What model of 1-wire alt is it - GM, Ford 3G, etc.? Some can be easily bypassed for diagnosis.

I believe that there may not be an issue with the VR, or the alternator. The Bronco sits for quite a bit each year. I don't trickle charge the battery the way I know I should. I found that last year, after I get a good 15 or 20 minutes of run time on the Bronco, the voltage gauge shows output. I'm not an electrical guy; but, I'm wondering if the fact that the batteries are slightly discharged when this happens may be part of the problem.

[/QUOTE]2) Find any ONE of the LB/R dimmed dash wires, and apply 12V to it. Regardless of key or light switch position, all the dimmed lights should come on full brightness. If they don't, they're either burned out or not grounded.[/QUOTE]

I will give this a try.

[/QUOTE]When you add grounds, don't just add them randomly. Start at the battery (-) cable, and make a continuous path, hitting as many metal objects as possible: core support, each fender, firewall, frame, engine... Make the firewall ground a pass-through bolt, and start another string inside the cab: firewall, dash, doors, t/g, top...[/QUOTE]

That's all good advice. I'll plan on reworking it in the future.

Take Care,

Jeff

 

[Jeff10]

Hi Guys,

I just responded to Steve regarding the alternator. Maybe not having a problem. I'll keep an eye on it the next few days.

Thanks for all the input.

Take Care,

Jeff

 

[Jeff10]

Hi Guys,

One more bit of information to add.

I recently did a headlight upgrade, complete with a harness upgrade from a member here on the board.

Tonight I was attempting to adjust the angle of the headlights. (I need to do a little more research into the correct height adjustment for the headlight beam when I have it pulled up against the garage door.)

I noticed tonight that when I pull the headlight switch out to the first stop/detent, the headlights go on. When I pull the switch all the way out, the headlights stay on.

I believe the parking lights should go on when I pull the switch to the first detent.

Any thoughts on where I should look first for this issue? I bought a new headlight switch... I just haven't made the time to install it yet.

Thanks for any advice you can offer.

Take Care,

Jeff

 

[DirtDonk]

This is your '71, right Jeff?
If so, then yes, the first pull AND the second pull should have the side-marker, front running lamps, and the tail lights all illuminated.
Do any of them work?

Whether you replace your switch or not, inspect the wire as they enter the connector that pushes on the switch. Often you find burned and corroded ones causing trouble.
Or the connector itself can be cracked. Though that last usually doesn't hurt the electrical function right away.

Ultimately, it could be the switch, the wiring, the lights, or the grounds. But they're not all on one ground point, so it would have to be multiple grounds (not impossible) and the other associated and nearby lights would not work either.

Paul

 

[Steve83]

I don't trickle charge the battery the way I know I should. I found that last year, after I get a good 15 or 20 minutes of run time on the Bronco, the voltage gauge shows output. I'm not an electrical guy; but, I'm wondering if the fact that the batteries are slightly discharged when this happens may be part of the problem.

Yes, using the alternator to charge a discharged battery DOES damage both the alt & the battery. A good float charger (BatteryTender or BatteryTender Jr.) is much cheaper than a battery or an alternator.

But you should still put the specific type of alternator into your signature. If you can't ID it, post a few good pics of it.

I need to do a little more research into the correct height adjustment for the headlight beam when I have it pulled up against the garage door.

It's really better to aim them on a light-colored STRAIGHT EMPTY road surface at night. Bring a dark towel to lay on the hood & block the headlight you're NOT aiming. Drive straight in your lane & stop without steering so the vehicle is pointed straight along its lane, centered. Adjust the L headlight's bright spot so it's (vertically) almost out-of-view in the distance, and (horizontally) well WITHIN your lane. Adjust the R very slightly higher, and close to the R edge of your lane. Pound on them to make sure they're settled into position, and won't shift as you go over bumps.

Do a few test-drives to make sure they're usable. Next time you take the headlight bulbs out of the grille, lubricate the slide pads & screw threads so they move more easily.

I believe the parking lights should go on when I pull the switch to the first detent.

Yes.

 

[September 1972]

I installed new battery cables. Quick crimp terminals and 1 gauge Mil Spec SAE cable which has the heat rating for under hood duty. A harbor freight 10K psi terminal press for 50 bucks comes with dies but I had to modify them to work. Di electric grease is slathered on the bare stripped cable like one would slather bacon grease on a bare strippers ass and one must pay attention to correct clocking of the terminal before you crimp it because it's not flexible. I pump the press until it bleeds to make sure it can never get loose.

The chassis has a lower resistance than any wire which many of you have discovered when attempting to bench test gauges. At an average of 5 volts and low current flow,any resistance in the gauge circuit is the kiss of death insofar that they won't work right.

The motor mounts connect to the frame and whatever bolt or bracket is common to the engine block where the negative cable is located and the frame, that's your ground gateway to the battery and treat it as electrical wire because it is.

The sub structure connects to the frame through bolts. The sub structure bolts are YOUR CHASSIS GROUND. The 8 donut bolts go through the floors and frame into a cage in the frame. Clean and apply grease to these bolts and treat them as ground wires, because that's what they are. I attach extra ground cables but you must understand that the extra cables should not be too close to the firewall because you may introduce a nasty ground loop into the vehicle. The body and chassis have near zero resistance, not so with wire.

Test. If I removed the taillight grounds from the inner body structure and bolted the ground wire to the best wire or cable known to man back to the front chassis and bolted it there, how do you suppose the taillights would work? They would barely light or not work at all.

Every connector from the battery to the fuse box and every other connector should be dismantled and cleaned and load tested within the capacity of the gauge wire with a 12V devise. When the wire in the circuit is under a load check for an excessive voltage drop from one end to the other and wiggle the connector. If the copper has changed to a grey color you are screwed and the wire must be changed, usually the running light wires have been overheated by supplying current to high wattage bulbs.

It's not hard to overhaul an electrical system and it's unnecessary to replace all the wire in most cases, Ford factory wire is good stuff. With a helper I can do it in 30 hours and there will be no question that the electrical system should be trouble free for years. Military spec heat shrink with epoxy sealer and a tub of grease will lock out moisture so cleaning battery terminals and replacing a switch or devise here and there is all you will have to do as the years pass.

 

[Jeff10]

Hi Paul,

This is your '71, right Jeff?
If so, then yes, the first pull AND the second pull should have the side-marker, front running lamps, and the tail lights all illuminated.
Do any of them work?

Whether you replace your switch or not, inspect the wire as they enter the connector that pushes on the switch. Often you find burned and corroded ones causing trouble.
Or the connector itself can be cracked. Though that last usually doesn't hurt the electrical function right away.

Ultimately, it could be the switch, the wiring, the lights, or the grounds. But they're not all on one ground point, so it would have to be multiple grounds (not impossible) and the other associated and nearby lights would not work either.

Paul

The status of the lights is that with each position there are three sidemarker lamps that don't operate. I haven't tried to troubleshoot yet (bulbs, wires at the bulb connector or at the opposite end of the harness).

I don't want to get too deep into any repair knowing that I might open up Pandora's box... and the Bronco needs to be running the next week.

I'll keep you posted.

Thanks,

Jeff

 

[September 1972]

Those little connectors are notorious for corroding and are hard to clean since they corrode deeply.

Put a 12v meter in the light socket and a known good ground with the switch on. Running light wires can and do get hard from high wattage bulbs and 50 years and can fracture. I think that the feed for running lights is a drop off the light switch and possibility the turn signal switch. Disconnect the connector at the base of the steering column that has about 8 wires and gently clean the terminals and grease and connect it.

 

[DirtDonk]

Yeah, don't delay more important stuff for sidemarker lights.
But know too that they're notoriously fickle in their work ethic. If you bump your fender and they flicker, then you know it's just the typical loose connection between the bulb and socket. Very fickle...

Often reaching up and giving it a little finger-flick-to-the-ear (like on a cold morning at the school bus stop, ya know?) and it works, then just pull them out, clean them up, insert some bulb grease to seal out the elements, and work your way around to all four corners and do the same thing.

When all the more important stuff is done of course.

Paul

 

[Jeff10]

Hi Again Everyone,

One more symptom that I can throw in the mix.

Today I tried the high beams. The red light on the dash illuminates when I depress the foot switch; but, there is no change in the light intensity.

The conversion was made recently using KC HiLiTES. I also used the headlight conversion harness from hyghlndr here on the board.

I know this thread is jumping all over the place... sorry. Just trying to add things as they come up.

Bronco needs to run for at least the next three days, so I really can't get into the electrical system too deep for fear I will keep the Bronco from running.

Thanks,

Jeff

 

[DirtDonk]

Well hell's bells Jeff. If it ain't one thing, ain't it just another!
Seems the floor switch is working or you would not see the dash indicator. That's putting power to the original wiring so the power is getting from there at least partially to the new harness.
Not familiar with that relay harness specifically, but you know they worked before?

Is it a standard relay harness, or is there a jumper to switch around if you want both high and low to illuminate at the same time?
Just thinking that if there is that option, then it's possible that something is amiss with it, or both of your high-beam filaments are burned out.

Going back a step here, but if your floor switch was truly working you would lose your low-beams when you switched because it's supposed to cut power to the relay.

Try this test. If the original headlight connectors are still intact, plug them into the back of the bulbs and see if you get high-beams now. If so, then there is something wrong with the harness or the relays themselves.

Paul