Turn signal problem

[stubby1962]

Hi All:
I have a 65 SWB/SS. I put a ZR-1 roll pan on it and cannot get my turn signals straightened out. I have parking lights, brake and one turn signal, But when I turn on the signal to either direction. Both indicator lights on the instrument cluster blink, but not on the front of the truck. I have all the lights grounded very good,(or at least I think I do). I had a similar problem before on a 76 Chevy truck I was hooking up a trailer light to and ended up getting a converter for it. Well I bought a converter and installed and still no luck with them. I have unpluged the front harness to the lights and The back lights work right, but the indicater lights still flash on the instrument panel..I've thought about splicing into the rear turn signals and running them up front to get the front blinkers working. Any suggestions would be greatly appreciated. Thank You and God Bless US All.....John

[Captainfab]

Welcome to the forum

It does sound like a ground problem, but it could also be in your turn signal switch. I had a problem with hooking up trailer lights once, that I fought for hours and hours. It ended up being in the turn signal switch, A couple of the brass contacts got bent and were making contact all the time. The switch will come apart so you can see them.

[willyp]

i had the same type problem. thought i had a good ground but i didnt....after pulling most of my hair out i figured it out my grounding out the metal part of the bulb...fixed! good luck.

[stubby1962]

Thanks for the replies. I installed a new turn signal switch when I installed the rollpan. I have the turn signals grounded to the same place I have my headlights grounded (in the front). In the back I have them grounded to the rear crossmember of the frame. They both seem to have good grounds.
I have temporarily ran 2 wires from the back to the front and hooked them up. The turn signals work, but when the brake is applied I have both lights coming on in the front, but I have them blinking.
I don't remember seeing a ground from the turn signal switch that I replaced. I have checked the continuity on the front harness and it checks out. I also checked for voltage on the firewall going to the harness and it is showing power and blinking like it is supose to.
If I ran a ground from the front to the back and grounded them in the same place, Do you all think it would work? What I don't understand is both indicator lights in the dash lighting up when I flip the switch in either direction.
Again I thank you all for your help and God Bless US All..John

[tincan1966]

Do you have a groud from the battery to the frame? I know you said the lights are all ground to the frame. I always run a cable from the engine to the frame.
Sound like the front harness may be your culprit, which is common. No need to run a bunch of uneccessary wires front to back for grounds. If it works normally with the front disconnected, I'd check the front harness from the firewall to the lights in the hood. Sounds like the left and right circuits are crossing in that harness.

[stubby1962]

Tin can,
Thanks for you fast reply. No I don't have the battery grounded to the frame, Just the motor. I will run one and try it. On the front harness I have separated the wires and checked continuity through them and they seem fine.
When I hook everything up(the way it's supose to) my blinkers flash real quick and both indicator lights in the dash light up..They flash so quick, you can barely see them flashing, but you can hear the flasher working overtime..LOL
I will try the battery to the frame and see what happens.. Thank You and God Bless US All...John

[stubby1962]

Found the problem with the turn signals...Apparently the turn signal switch wiring harness connector was not making a good ground...After pulling out what hair I have. I decided to check inside the truck. After pulling the steering wheel off and looking at everything there (looked like it should). I grabbed the harness connector to disconnect it and the turn signals started working properly..apparently the ground did not have a good connection, but now it does..and I'm a happy camper...Thanks for all your input on this problem. Again Thank You All and God Bless US All...John

[K98AL]

What did your turn signal switch ground to? I have turn signals, but no indicator in the dash - when my signal is on, I can ground my test lead to the frame, and get power from the socket, when I turn signal other way, I can do the same thing. For some reason it's not grounding the indicator - I can't just ground the socket, because it reverses polarity.....I changed the switch already, didn't make any difference.

[stubby1962]

I don't know what my switch is grounded to. I think in the column under the steering wheel. My problem was where the turn signal switch harness was connected to the harness under the dash. Where the two male and female harnesses connected together. My indicator lights on the dash were working, both at the same time. Maybe it's not getting a good ground in the column under the steering wheel or possibly a fuse. Were they working before you changed the switch out? John

[K98AL]

No - dash indicator (there's only one) hasn't worked since I got the truck. I got both rear turn signals working, but still no dash light indicator. Yes, there's only one indicator, it serves both directions.Go figure.

[tincan1966]

K98AL I'd check to make sure the instrument panel is grounded to the body good. Also, do you have a 10ga wire from the negative battery post to the radiator support? That is how GM grounds the body. Inaddition, there should be 1 or two(dependiing on 6 cyl or V8) copper wooven ground straps from the engine to the firewall. All of these things should be in place. There are no seperate fuses for the turn signal indicators. The wiring in these trucks is horribly simple.
If you have power to the turn indicator socket when using a test light with alternate ground, then you have a grounding problem at that socket. To test, install a known good bulb, turn on turn signal and touch the outside of the socket with your test light(other end of test light still connected to good ground) if the light blinks, then the socket is not grounded good when installed in the cluster. This will save you some time chasing harnesses. I would recommend running a 14ga wire from a cluster mounting screw to the body under the dash. Originally GM uses the mounting screws as a ground source, since the clips are bare metal and "bite" into the dash. Most ofthese trucks have been painted at some time and the clips get covered.

Hope this helps.

[K98AL]

I will check all of these - Thanks for the help!