83 K10 no turn signals with headlights on?

[71GMCNC]

Hello everyone. I have an 83 K10 and when my headlights are on you can see the hi beams on every so slightly. On top of that I have no turn signals up front but have them rear. With the headlights off everything acts as normal. Also the headlights are dim. I replaced the alternator and the battery is an optima red top. Anybody have a suggestion on where to go next?

[92470]

I had the same problem with my 87' and after weeks of troubleshooting everything, found out I had a bad connection from my lower headlight (high beam on a dual headlight grill) to the ground that bolts into the upper radiator support. On mine all worked well, until I turned on my high beams and right turn signal. I posted the question also, and everyone said it had to be a ground, and it was. My advice is to check all your grounds to make sure you have a solid, clean connection and that you don't have any frayed or broken wires. I bet you that's what it is. Bad ground somewhere. Good luck.

[71GMCNC]

I'll give it a go. Think while I am tinkering I may add some extra grounds or grounds that are possibly missing. I am thinking battery negative to block, frame, upper radiator support. Right now the upper radiator is grounded with the smallest cable in the world. lol.

[cor86]

I agree that it is a ground problem. Do the big 3 (0-4 gauge wire, alt-batt/batt-eng/batt-chassis) and check the grounds on your headlight wiring harness. If you can afford it, now would be a good time to add relays and make your own harness, using 12 ga. wire and new light sockets from any autoparts store.

[leegrady]

Turn signals don't work when the headlight are on? What do the turn signal indicator lights do? Check for poor ground at the instrument cluster, bad connections at the fuse, and damaged printed circuit board. Also check for ground straps from the valve covers to the firewall.

[71GMCNC]

Ok this weekend I am going to go to it. I checked and with my lights on the turn indicators in the cluster work fine and the rear turn signals illuminate. I think I will go to the parts store and invest in good ground wires and do the big three. What is this relay harness thing that ya'll were talking about?

[cor86]

Here is a diagram for a 2 headlight system. The 30A relays can be found almost anywhere, including parts stores. I can't remember what the colors are for the stock low and high beams. Tell you what, do an advanced search with headlight relay, titles only, and you will be reading for awhile.

[71GMCNC]

I really like that setup. Think I may go ahead and build that harness while I am at it. Gonna spend the weekend working on the interior and grounds. Thanks for the diagram cor86!

[cor86]

No problem. Just make sure to replace the headlight sockets and ground terminals. Check the turn signal wiring for brittleness while you're at it. Those sockets probably need replaced, as well. Spend some time making it look good, and use wiring loom! There's nothing worse than being too embarrassed to open your hood (I'm still replacing the PO's "fixes"). Good luck and have fun!

[leegrady]

Great diagram co86. Fyi: If I'm not mistaken GM used a circuit breaker instead of a fuse for the headlights. The headlights will blink on and off if the circuit breaker trips.

[71GMCNC]

Ok, a little update on what I accomplished and what I have come up with. So I redid the 4 gauge grounds from battery to frame, battery to block, and battery to radiator support. I have solved my headlight issue it now only lights the lows when I am low and all four while on high. The turn signal issue still exists. With headlights on the turn signals do not blink up front. After looking at the wire diagrams it leads me to believe the headlight switch has a short in it. All wiring was verified correct. So I am going to order one tmr and see if thqat fixes it. Wish me luck!

[71GMCNC]

Ok got the new headlight switch and installed it and everything works as it should. I am guessing there was a short when the switch was in the on position grounding the system. Thanks to all for ya'lls help! Yet another reason I love this board!