Mopartisus
Well-Known Member
The voltage at my taillamps is around 8-9-10 volts, fuses are clean, ran a ground wire from the battery to one side and no difference. scratching my head on this one.
Low voltage at taillamps
- Thread starter Mopartisus
- Start date
I'm not wiring guy, look for harness plugs for corrosion and pinched wire. Work your forward until you find 12v.
Moparnocar
Well-Known Member
I just had a big voltage drop at the fuse box. Pull it, and compare fuse holder to the actual power wire to the box. Could be through turn signal switch too
R413
Well-Known Member
Remove the sill plate and kick panel on the drivers side. There is a 6 blade connector behind there, check for your power there and see if the voltage is better. Could have a problem in the headlamp switch or fuse box. What is your battery voltage? Might try putting a battery charger on it to keep from draining th battery whil the lights are on.
Taillamps don’t go through the turn signal switch, but the rear stop/turn lamps do.
Taillamps don’t go through the turn signal switch, but the rear stop/turn lamps do.
67 GTX
Well-Known Member
I didn't have 8 volts, but at my headlights I was getting 10 volts. Then I went through and cleaned every contact that I could find, and I got it up to 11 volts at the headlights.
I was told that some of the loss could be from other places I couldn't find, or normal degradation in the wiring accounting for the loss.
I was told that some of the loss could be from other places I couldn't find, or normal degradation in the wiring accounting for the loss.
Did you clean contacts in bulkhead connector?
Mopartisus
Well-Known Member
Thank you all. I saw there was a 6 prong connector in the FSM but couldn't figure out where it was. I will check there and then the fuse box, then bulkhead connector (although I'm afraid to touch it). I'll report back what I find.
Matt
Matt
Painting my engine compartment removed wiring. Plugged it back in one female connector got unhooked and had to plug in back in from under dash.
Mopartisus
Well-Known Member
Planned on detailing the engine compartment/engine/suspension the last three winters but snowmobiling keeps getting in the way.
Mopartisus
Well-Known Member
Was able to test voltage at the 6 pin plug behind the kick panel. Same wacky voltage numbers as the rear. Then took the fuse box down and have full voltage at all circuits. I'm guessing that would lead me to the turn signal switch? Stop/turn lamps are what I meant to say when I originally posted.
Moparnocar
Well-Known Member
Do have wacky voltage at both sides of the fuse AND the wire TO the fuse in the back?
miller
Well-Known Member
Could be the condition of the wiring itself.
You'd be better off, doing an ohms test, on 'each' wire segment, in each wire harness. Such as, the segment that goes to the rear...starts at the kick panel, under the sill plate, into the trunk area.
As on mine, when I checked all my harnesses, figured 1 ohm max, for a useable wire. Any more...that wire was replaced. Need a good ohm reading, before a wire will pass voltage from one end, to the other.
You'd be better off, doing an ohms test, on 'each' wire segment, in each wire harness. Such as, the segment that goes to the rear...starts at the kick panel, under the sill plate, into the trunk area.
As on mine, when I checked all my harnesses, figured 1 ohm max, for a useable wire. Any more...that wire was replaced. Need a good ohm reading, before a wire will pass voltage from one end, to the other.
Mopartisus
Well-Known Member
No, voltage at both side of the fuses are good.
Moparnocar
Well-Known Member
What about BEHIND the fuse? With the lights on, do all three spots read low?
62 Dart Convertible
Well-Known Member
Sorry Miller, I can't agree with that. Picking an arbitrary 1 ohm for OK/not OK is no good. Depends on length. 1 ohm would give a 1V drop if carrying 1 amp, and with only 12V to start with, a 1V drop per amp in a brake light circuit say would be no good at all. Better off measuring voltage at every point possible and finding where the voltage is being dropped. One can also measure voltage between points of wiring to measure actual voltage drop across a suspect connection or a length of wire.
miller
Well-Known Member
That's okay. Either check works...it's the end results that matter.
Agree the length of the wire is part of the play. Ohm checking is done, the full length, from one end to the other.
I re-used, and rebuilt my 64's wiring harnesses, for the main part. Highest ohm reading I got was 0.4, well under 1 ohm. ALL of my wiring works great...some of it 50 years old.
Too many things can cause voltage drop. Poor connection, corroded wire, and so on.
But, use whichever test is easiest, for the tester. Results is what matters. If the wire is in good shape, it will pass the full voltage.
62 Dart Convertible
Well-Known Member
Do you have a factory wiring diagram? If not, you need one. You just need to follow the path from fuse box and through each connector measuring the voltage to earth on both sides of each junction. It will be obvious where your voltage is being dropped.
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