Electrical mystery.....

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RustyRatRod

RustyRatRod

I was born on a Monday. Not last Monday.
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Alright boys, I got a goodun. Get this. My driver's side reverse light is hot when the ignition is turned on. No biggie, probably something up with the reverse light switch or wiring. Gotta pull the transmission back out anyway, so I'll look at that then.

Anyway.......The passenger side light doesn't work. However, it has power AND ground going to the bulb. The bulb is good. How do I know? I took the driver's side bulb out and swapped the passenger's side bulb in. Bam it burns. Put the driver's side bulb in the passengers side and nothing. So what could be goin on here?
 
RustyRatRod said:
Alright boys, I got a goodun. Get this. My driver's side reverse light is hot when the ignition is turned on. No biggie, probably something up with the reverse light switch or wiring. Gotta pull the transmission back out anyway, so I'll look at that then.

Anyway.......The passenger side light doesn't work. However, it has power AND ground going to the bulb. The bulb is good. How do I know? I took the driver's side bulb out and swapped the passenger's side bulb in. Bam it burns. Put the driver's side bulb in the passengers side and nothing. So what could be goin on here?
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Are you positive that the socket is grounding to the housing and you have a good ground?
 
I’ve had to rebuild many of these old sockets over the years.

I also usually add an external ground wire from the housing to the body as an insurance policy
 
If it has power it has to be right there in the socket I'd say

Years ago, the 4509 or 4537 aircraft landing lamps were popular for various things, I had sold a pair and some housings to a customer. Came back in mounted on a 62 ish Ford pickup. Could not get them to work. The bumper was so rusty it was not grounding to the frame!!!
 
67Dart273 said:
If it has power it has to be right there in the socket I'd say

Years ago, the 4509 or 4537 aircraft landing lamps were popular for various things, I had sold a pair and some housings to a customer. Came back in mounted on a 62 ish Ford pickup. Could not get them to work. The bumper was so rusty it was not grounding to the frame!!!
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Well, it does have some surface rust, but I checked the tail light housing to ground with my meter and it has continuity. The middle contact has power. So, it probably is the socket somehow.
 
My guess would be the socket isn't grounded properly. My old dodge pickup did some crazy stuff and low and behold the driver side rear taillight socket wasnt grounded. The wire was there everything looked normal but the bolts that held the socket in where rusted and it wasnt grounded.
 
Try a load light on it by chance? If it is a bad connection just say still one strand of wire you will read 12v but no amps. Just an idea.
 
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RustyRatRod said:
The middle contact has power. So, it probably is the socket somehow.
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If memory serves, I had an issue like that once. They USED to sell the little board with the contacts and about 6 or 8 inches of lead on the wires that you can replace the old one with.

I don't know if they still sell them or not.
 
I recently saw the rebuild kit for 1157 2 wire by 3/4 dia. socket at Amazon so I'll assume any are still available. If the reverse lamps, one or both, are on at all times, the reverse lamp switch is most likely culprit. Where that switch is varies with year model.
 
Anybody check tail lamp housing to body ground? I’ve seen bad connections there too.
 
fklskv said:
Thats why a Power Probe is the best tool you can have.
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You don't need an expensive tool to trouble shoot this. A dime store 12V lamp and or an old tail/ stop socket with an 1157, and a meter. YOU ALWAYS need a meter. I just bought three more Flukes off C/L for 25 bucks apiece. They are beaters and they work
 
67Dart273 said:
You don't need an expensive tool to trouble shoot this. A dime store 12V lamp and or an old tail/ stop socket with an 1157, and a meter. YOU ALWAYS need a meter. I just bought three more Flukes off C/L for 25 bucks apiece. They are beaters and they work
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Power Probes are not expensive (You dont need the whole kit)and if you ever use one you will know why test lights and multimeters take the back seat.
 
fklskv said:
Power Probes are not expensive (You dont need the whole kit)and if you ever use one you will know why test lights and multimeters take the back seat.
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I know EXACTLY what they are and YOU DON'T NEED THEM. You are implying they are a "must have." Perhaps you could explain "why this is"

a cheap junk (or even bought new) tail/ stop socket and lamp does many things at very little money. The lamp puts a load on wiring which can show up bad connections that a simple volt /ohm test might not, and they can be used to protect circuits when hunting a short. I used to use them in series with a battery charger on small bike batteries. The uses are many. You can configure the assembly for higher or lower current draw And, LOL, it has a "built in" spare stop/ turn/ park / tail lamp................
 
67Dart273 said:
I know EXACTLY what they are and YOU DON'T NEED THEM. You are implying they are a "must have." Perhaps you could explain "why this is"

a cheap junk (or even bought new) tail/ stop socket and lamp does many things at very little money. The lamp puts a load on wiring which can show up bad connections that a simple volt /ohm test might not, and they can be used to protect circuits when hunting a short. I used to use them in series with a battery charger on small bike batteries. The uses are many. You can configure the assembly for higher or lower current draw And, LOL, it has a "built in" spare stop/ turn/ park / tail lamp................
Click to expand...
 
I am a retired journeyman diesel mechanic. I have worked on countless trucks with millions of miles on them and every kind of electrical problem you can think of. I have convinced many mechanics to give up on test lights and multimeters and buy a Power Probe of which none go back.

If your happy with a test light and mulitmeter I’m not going to try and change your mind.
 
The BEST way to test a circuit is to stick the hot wire in your but and the ground wire in your mouth, or is the other way?

Note- works best with voltage over 120V.
 
fklskv said:
I am a retired journeyman diesel mechanic. I have worked on countless trucks with millions of miles on them and every kind of electrical problem you can think of. I have convinced many mechanics to give up on test lights and multimeters and buy a Power Probe of which none go back.

If your happy with a test light and mulitmeter I’m not going to try and change your mind.
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No need to be condescending. I've never even heard of one. I don't do a lot of electrical diagnosis. Instead of put me down for what I do use, you could inform me of what it is.
 
RustyRatRod said:
No need to be condescending. I've never even heard of one. I don't do a lot of electrical diagnosis. Instead of put me down for what I do use, you could inform me of what it is.
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I agree what's a power probe never heard of one?! I have fault my fair share of electrical headaches anything to make it easier I'm in!
 
I don't want to get sucked into the pissing match above, but I got a PPIII for Christmas two years ago and it kicks ***.
 
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