Turn signal weird behavior - rears only on 97 1500
#51
10-02-2020, 06:53 PM
The various switches operate by supplying power to the correct bulb/filament. So, I think the hot ticket here is to pull all your bulbs, and test one system at a time. Do you get power to the socket on one of the terminals in there, when you apply the brake? Do you get power to that same terminal (switch on/off) with the turn signal for that side activated? Do you get power at the correct spot with the parking lights on?
Got a flashing pulse of 12V on the lower right terminal as you look into the socket with the 3 wires sticking out the top. No other power on the other 3 terminals.
Turned off turn signal and engaged brake. Got constant 12V ON THE SAME TERMINAL, and nothing on the other 3.
Stopped testing and came in to report :-)
#52
10-02-2020, 08:43 PM
Okay. Very interesting. Ran a long wire from the negative terminal/cable at battery back to rear of truck and connected to one of my ohm meter wires. Then:
Disconnected the rear tail light connectors for both Driver & Passenger and ...it's a mess: Testing for continuity on the 4 wires - there was no continuity for the Black Ground wire, however, there was for both the Black & Yellow (Power?) striped wire as well as the Brown & Violet(Pink) on the Drivers side and same on Passenger where the Black Ground had no continuity, but, the Black & Yellow did as did the Green & Red. The other wire in both connector had no continuity.
The license plate lite(s), both black wires had continuity.
Didn't bother putting bulbs in one at a time as I know my wiring is screwed up. Just not sure what to do next.
Disconnected the rear tail light connectors for both Driver & Passenger and ...it's a mess: Testing for continuity on the 4 wires - there was no continuity for the Black Ground wire, however, there was for both the Black & Yellow (Power?) striped wire as well as the Brown & Violet(Pink) on the Drivers side and same on Passenger where the Black Ground had no continuity, but, the Black & Yellow did as did the Green & Red. The other wire in both connector had no continuity.
The license plate lite(s), both black wires had continuity.
Didn't bother putting bulbs in one at a time as I know my wiring is screwed up. Just not sure what to do next.
Last edited by DerTruck; 10-02-2020 at 08:49 PM.
#53
10-02-2020, 09:13 PM
Please don't confuse yourself. The black not having a ground connection *IS* a problem. The black/yellow connect all the tail/marker lights and will find ground via the front light bulbs or license plate bulbs so that's no cause for concern. The green/red and brown/pink should be connected to each other with the turn signals off, but shouldn't see ground. By any chance do you have a trailer hitch with the 4 and/or 7 pin connection ?
#54
10-02-2020, 09:40 PM
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#55
10-02-2020, 09:49 PM
I don't understand. I already said I was getting continuity to ground on the black & yellow as well as the green & red or brown & violet... Do you mean for the back up light sockets?
#56
10-02-2020, 09:52 PM
#57
10-02-2020, 09:56 PM
I did go and check a back up light socket and neither post/terminal has continuity to ground :-)
#59
10-02-2020, 10:06 PM
#60
10-02-2020, 10:06 PM
There are two things off: All black wires should have ground connection, and you state only the license plate ones do. The brake/turn signal wires should be "floating open" unless the brakes are applied or one of the turn signals is on. Just to make sure, you are looking towards the truck, not the lights ?
I'd say it's time to bite the bullet and drop the spare tire. The wiring harness splits somewhere on the driver side above the spare. The splice for all the ground connections is hiding somewhere near the junction according to the FSM. Open up the loom a bit and look for corrosion or rubbed through wiring.