Chevy truck wiring

[oldman45]

Any Chevy men out here?

I have a Chevy 3500 dually. The lights, brake lights and such are working fine. The left rear turn signal stopped working this week. I got time today to replace the bulb. Not the problem. Checked all the connections. All tight.

The front left signal is working at double speed.

Anyone got a reason for it not working?

 

[Mickey D]

If the bulb is indeed good(I've seen bad new ones), then you most likely have a bad ground on the LR light. The corrosponding 'other' turn light flashing at double speed indicates the other is not working.

Try changing the bulb again.

 

[26Ford]

Could be as simple as the new bulb being bad, or the socket itself, or a ground wire. If not, then you are left with the harness and starting from the bulb socket work foward thru the harness.
It is normal for the remanining signal on that cicuit to flash at high speed, if one of the circuits can't be completed.
If you have a test light or a multi-meter, do your basic checks for voltage at the socket. Should be approx. 12.6-12.7 volts. The test light should flash with the signal activated. If using a meter, it will alternate back and forth from zero to battery voltage. Use a low D.C. scale on the meter.
Let us know what you find OK

 

[oldman45]

Let me ask this.

Many years ago, cars had a flasher under the dash.

Do they still have them? Somewhere in the back of my mind from the 50's, I seem to remember they could go bad and cause problems but maybe that was just not letting the lights flash.

 

[26Ford]

Depending on the year of the truck, the flasher could be under the dash, or even under the hood. Probably with the fuses and relays. If your other signal/side is flashing fine, its probably not the flasher. You might have 2 flashing units, if you do one would be for the turn signals, and the other for the 4 way or hazard flashers. 26

 

[26Ford]

Was there any water in the socket or the area where the bulb was taken out of? You can spray a little WD-40 in the socket and try that. Remember WD-40 will displace the water.

 

[26Ford]

You can test the new bulb, right from the battery with 2 small pices of primary wire, if you dont have any test leads. I would do that first my friend.

 

[cussedemgun]

When tracing wires for a trailer hook-up or such, many use a tester that has a bulb & a sharp probe to pierce the insulation to check for power. Oft times that tiny puncture of the insulation jacket will let in moisture leading to corrosion & failure. I can't be sure about your truck because you didn't state year, but many American brand cars & trucks share the same eliment in the double eliment bulb for both brake light & turn signal. Short story, if that side brake light works, check for intermittent voltage with the turn signal activated. If no voltage to the bulb button, it's prolly a busted wire.

 

[26Ford]

He's right, dont stick/probe thru the wire insulation if you dont absolutely/positively have to.

 

[KJM]

Let me ask this.

Many years ago, cars had a flasher under the dash.

Do they still have them? Somewhere in the back of my mind from the 50's, I seem to remember they could go bad and cause problems but maybe that was just not letting the lights flash.

Yes it does and that could be the problem. First thing I would check in fact, as it is the easiest and most likely problem.
There is one for the 4 ways and one for the signals... look in owner manual as they may be under hood in the box over near the master...
And it COULD just affect one signal.... I've had several go bad over many years....

 

[oldman45]

When tracing wires for a trailer hook-up or such, many use a tester that has a bulb & a sharp probe to pierce the insulation to check for power. Oft times that tiny puncture of the insulation jacket will let in moisture leading to corrosion & failure. I can't be sure about your truck because you didn't state year, but many American brand cars & trucks share the same eliment in the double eliment bulb for both brake light & turn signal. Short story, if that side brake light works, check for intermittent voltage with the turn signal activated. If no voltage to the bulb button, it's prolly a busted wire.

I have several of those testers laying around. It is likely I have about one of every tool sold by Craftsman. What I am lacking is intelligence on wiring and time. This is a project I will have to deal with Sunday since it is getting late today and I have to work a security detail tomorrow.

Please feel free to post ideas and suggestions.

 

[oldman45]

Just checked the lights with someone else working them.

The left turn is not working. The 4 way flashers are not working at that light.

The brake light is working.

The tail light is working.

So only the left turn signal and 4 way is not working at that position.

 

[RightArm]

Did you check the blinker fluid and make sure it is the right level. You could be leaking fluid.

 

[oldman45]

Did you check the blinker fluid and make sure it is the right level. You could be leaking fluid.

The unit is sealed by high speed duct tape. Not leaking,

 

[DeathGrip]

The unit is sealed by high speed duct tape. Not leaking,

Sometimes the leak is internal and you can't see it. Blinker fluid if it's old will allow corrosion and even break down the secondary seals within.

Caution!!! Only use a vacuum bleeder to assure that you have flushed all of the old fluid and gotten the air out.

Another little secret is to add a little vinegar to the fluid to help remove calcium deposits.

Cheers,

 

[oldman45]

Sometimes the leak is internal and you can't see it. Blinker fluid if it's old will allow corrosion and even break down the secondary seals within.

Caution!!! Only use a vacuum bleeder to assure that you have flushed all of the old fluid and gotten the air out.

Another little secret is to add a little vinegar to the fluid to help remove calcium deposits.

Cheers,

Baking soda works best. Also creates less wind drag.

 

[26Ford]

The unit is sealed by high speed duct tape. Not leaking,

Yes, but did you use the negative ground duct tape. The positive ground duct tape is to only be used on the older Brittish cars and motorcycles.

 

[26Ford]

I know you have been having trouble submitting pictures lately, I thought I would post this for you..................

 

[Marshall 357]

I am not a Chevy guy, but I had the same problem on my Dodge Dakota.. On the Dakota inside the cab by the fuse box is a [ I guess you could call it the beginning of the wiring harness] with wires going into the "board'' I turned on the turn signal and testes each hole with a tester..when I found the hole I was looking for the tester light started to flash I just ran a new wire from that hole to the rear turn signal.I had to strip the wires at the light socket to fine out which one to use, just had to touch the hot wire to each one and the one that made the light flash was the winner. connected the wire and sealed the splices with heat tape and It has been working fine since then. Good luck

 

[DeathGrip]

Baking soda works best. Also creates less wind drag.

Just make sure it's at less than 70 degrees. It always seem to not mix well at higher temps. For summer use I prefer the vinegar.

Added bonus either one makes your blinking smell fresh....er.