Idk if anyone here remembers me. But I had a 96 1500 that got sold cause of the rise in gas prices.

Anyway, I just recently acquired a 94 shadow. Nice little car. Needs some work though, and it has an interesting electrical issue. I was going to post it in the K-car forum, but I swear I can hear the crickets over there, so I'm hoping someone over here in my old forum can help me out.

Here's the problem. The turn signals do not work. And the brake lights do not work, under certain circumstances. I think these two issues are related. Here's why.

When the parking lights are off, the lower brake lights and high mount lights work. However, the brake lights that come on are not the brighter filament of the bulb. The ones that light up are the dimmer filament. The turn signals do not work.

When the parking lights are on, the high mount brake light works when the pedal is pushed, but when the brake pedal is not being pushed, they still have some small amount of voltage going to them, because they light up very very very dimly. The parking lights light up normally as they should (The dimmer filament I mean). When the brake pedal is pushed, the parking lights shut off (the dimmer filament) but the brake lights do not go on (the brighter filament). The high mount brake light lights up as it should. The turn signals still do not work.

Now when I say the turn signals do not work, I mean that they don't flash. They light solid. I replaced the flasher, and this did not change
All the bulbs are new.

So what's shorted to where and how the hell can I find it?

 

You have a bad ground condition. The reason your lights behave the way they do is that the common point of both filaments is the ground point. If the ground is bad the filaments become connected in series instead of parallel which will light them dimly.
Try putting an ohmmeter on the bulb casing and check to the sockets. You should have zero or very low readings. If the readings are high remove the bulbs and polish them & sockets. If the readings are low remove the housings and clean up the contact points and re-install. Check for good conductivity again. Continue until all grounds are good.

 

Thanks. I'll start that tomorrow. I was thinking thinking the sockets looked a little corroded.

 

If memory serve me right, the brake lites go thru the turn signal and then to the brake switch. You may want to ck the turn signal switch.

 

Damn I hope it's not that... I really hope it's just a ground issue.

 

Okay I measured the resistance in the tali light/brake light sockets.

Pass side was out of limits/no resistance. Driver's side was in the 20 mega ohms area on both tail and brake light terminals.

Does this mean the socket is bad or does this mean there is a break somewhere?

I'm having a hard time remembering my electricity class. I don't do much electrical work. Mostly mechanical stuff.

 

You are looking for a resistance value near zero, for a maximum current flow, for bright lights.
What you have is a high resistance, meaning low current flow, giving you dim lights
You said passenger side was "out of limits/no resistance" did you mean zero resistance or infinite resistance? If you used a digital meter it should have shown 0.00 ohms for a good connection. If an analog meter the needle deflection should have been to the left.
If the reading was anything other than 0.00 or something close, or the deflection was to the right you had a high resistance. Both mean you need to clean the contact points between the bulb and socket, and then maybe the socket to the body of the car.
I hope that is clear, if not I will try to reword it.
I just re-read your post and it looks like you read the terminals instead of the bulb casing to the socket. The terminals would only give a reading on voltage. Resistance would be high or infinity since the switches are not in the on position and there is no circuit possible to ground. That is some good news because it tells you there is not a grounded wire making a connection to the chassis.
Read the resistance from the BODY of the socket to a good ground and see if the readings are like I described in the first part of the message. SORRY!!

 

Ah, now I gotcha. So from the ground portion of the socket, to the body. Got it.

I talked with anther buddy of mine and he suggested replacing the sockets (Since their cheap) and grounding them separately from the factory wiring to the body. And if that didn't work then there is a short to power somewhere. I think either the grounds are bad like you said, or there's a power wire coming in contact with a ground path.

The car has been sitting for about a year. There were no mice or other critters in it, and nothing looks chewed up in the car itself.

And yes, I am using my Fluke 78 Digital meter. And there was an infinite resistance meaning the meter displayed - O L - . But I think I did it wrong.

I'll check again in the morning with the socket ground to body thing.

 

The infinity and 20 megohm readings from the posts to ground shows there should be no problem with the feed wiring like your friend suggested. Standard resistance requirements for ALL voltage levels is 1,000 Ohms per volt. For 12 volt insulation that would be 12,000 Ohms, so you are in great shape. If you narrow it down to just the sockets you can use a scotchbrite pad to clean the inside surface where the bulbs make contact with the socket. They will polish the surface and not leave residue like steelwool would which can cause problems. If it is the socket to body connection you van run a jumper from the current ground position to a better ground point if necessary.

 

Okay she's all fixed now!

I ran a jumper from a good ground point, turned on the hazards, and touched the socket casing. Doing this lit up the brighter filament!

Sweet.

Went to go get new sockets, since no matter how I polished them, it didn't work. Dealer only item since it's so old.

Oh well. I ghetto rigged the sockets. I took out the ground wire from sockets and soldered in my own ground wire, and then grounded my ground wire to the body of the car. They both work now, and turn signals work. They aren't really soldered all that great, so when I get a chance, I'll go over to the dealer and get a couple new sockets.

So in conclusions, the socket casing wasn't bad, it was the casing to the wire connection. The one with the clamp on it. When I ripped them out, they were covered in corrosion.

Anyway, she's all fixed and working good now. Thanks for help man!