help with turn signals

[tomshortwide69]

I installed new aaw wiring harness and a new cpp tilt steering column have only 2500 miles on restoration turn signal fuse keeps popping anybody else having this problem thanks in advance

[VetteVet]

The turn signal fuse controls three circuits. Brakes/Turns, and tail lights.
A short in either of these circuits will blow the fuse. The turn signals are the only ones that require the ignition to be on. Here's how to trouble shoot.

1. with the key off, step on the brakes, does the fuse blow?
The brake lights and the turn signal lights use the same wiring and bulb filaments through the turn switch, to the rear of the truck. If the fuse does not blow then the problem is most likely a pinched wire in the turn switch.

The hazard lights also work with the key off and should blow the fuse as well

If the fuse blows then it may be a pinched wire in the column or a shorted wire in the wires to the rear. If you have the original color code the two turn/brake wires will be dark green for the right side and yellow for the left side. Your column harness may be different colors so we can sort that out.

If you have a multi-meter and are familiar with using it, finding the short is fast and easy. But first you have to identify the brake/turn signal wires and the other wires.

With the column harness plug disconnected, and the meter set to ohms, check for less than 1 ohm between the yellow and dark green wires and a good ground, that go to the rear of the truck. If you pull the bulbs you should get infinity otherwise you will read the resistance of the bulb, but it should read more than 1 ohm. I don't remember the reading of the 1157 bulb filaments. I think it's around 75 ohms though.

If you get a high ohms reading then the short is most likely in the column. Did the fuse blow in both directionals or in one or the other?

This is the typical turn signal column connector in a crescent shape, The aftermarket ones may come in a flat style with an adapter.




Notice that the wire positions and the colors may not match, but usually the
wires are located as follows.

1. Black- horn wire from horn relay.
2. front parking light
3. front parking light
4. Brown hazard lights
5. Violet-for turn signals
6. Dark green- right turn signal
7. Yellow left turn signal
8. White for brake lights

These match the connector in his left hand. They are also the colors in the wiring diagrams.

Once you identify the turn signal wires from the column you can check them with the multi-meter for resistance to ground. Connect the meter red lead to either the yellow or dark green wire and the black lead to ground. Then select the left or right turn with the TS switch and look for the low ohm reading. If you get it then the short is in your column and the switch is shorted or one of the wires is pinched. You won't need to have the key on for the meter checks.

2. with the key off turn on the lights, does the fuse blow?
The park lights run through the headlight switch and should not blow the fuse.

Hope this helps. VV