[rexs73gto]

Hey guys I need some help, I am having problems & I hate electrical problems because I'm no good with them. My turn signals will work , kinda. When I use the right it seems to work ok but it flashes a bit fast & jittery. The left won't work unless the park or headlamps are on & then they are dimm in back & it makes the GEN. lamp flash with it. When I use the righ it makes the gas gauge go past full & the temp gauge go past 250. I can hear the flasher unit clicking but it's louder on the right side. I've found the ground behind front fender brace, it's clean & tight. I ordered a new circuit board for the dash becaues of this & the turn lamp indicators don't light up when in use also. Any ideas or if you have had this happen & can tell what to look for I'd really appericate it. Now because I forgot to say it's a 73 GTO that i'm having the problems with. It has a new engine harness but not the front lamp harness. The engine harness had been cut on over the years so I replaced it but the front lamp harness had never been cut on so I didn't replace it. The new one was less the 3 years ago. When I took the car apart several years ago everything worked then. When I put the new harness in I don't know if it all worked as It took me a long time to get everything back together. Any help ,,, Please. Rex.

[sport coupe]

Gauges peg when they are grounded. One of the light circuits is back feeding problems to the instrument cluster. You can try taking out all the light bulbs and see if the gas gauge and the temperature gauge still peg. Taking out the light bulbs should disconnect back feeding if the problem is in the wiring or the wrong light bulbs or sockets.

[camerjeff]

Most turn signal ot tail light problems are caused by a bad ground at the individual tail light sockets. The ground depends on the conection of the tab on the sockets to a spot on the tail ligh housing, then the housing depends on the conection to the body, and the body to the frame. Lots of places for corrosion to build up.

For T/S I would rig up a temperary groung wire to each tail light socket, and take it directly to good ground on the body. I had a 69 GTO that had front brake lights for awile, the front turn signals would come on when the brakes were aplied, but not the brake lights. It also was a bad ground to the tail light sockets.

Other causes could be the wrong bulbs installed. Just something to look at.

Good luck with it!!!! I know they can be fustrating.

[rexs73gto]

Jeff on my 73 GTO the tail lamps & the front turn lamps all have ground wires, the turn signal housing is plastic so it has a ground built in the harness both front & rear. How should I put a ground on the T/S when it is already grounded?? Same with the rear?? Do you know if there is any other ground wires in the 73 front harness that maybe I didn't hook back up, or where it should be? When I checked the wires with a test light It worked the same on the test light as it does when I turn the T/S on. ??? When I tested the ground wire with the test light , I probed the ground with it connected to the Neg. battery side & nothing different happened which I though it would. I thought it would use the test light as an extra ground but nothing different happened????... ? Any more ideas would help. I'll try any thing at this point.

[rexs73gto]

Sport you said wrong bulb, I have some new led bulbs in my dash & was wondering if you think these may be the problem. They look great in the dash & are nice & bright but are they the cause. I've got a new circuit board coming in a few days as the old one I'm sure was bad as it was coming apart & turning black under the film. All the sockets are GM style sockets & are clean , plus I've cleaned the connection on the sockets to make sure they make good contact. I'll try just about anything at this point to make them work as they once did , if you have any more ideas please let me know as I said I hate electrial. I'm good with the engines & trans , but wireing I'm at its mercy. Thanks Rex.

[Old Goat 67]

Originally Posted by rexs73gto

Jeff on my 73 GTO the tail lamps & the front turn lamps all have ground wires, the turn signal housing is plastic so it has a ground built in the harness both front & rear. How should I put a ground on the T/S when it is already grounded?? Same with the rear?? Do you know if there is any other ground wires in the 73 front harness that maybe I didn't hook back up, or where it should be? When I checked the wires with a test light It worked the same on the test light as it does when I turn the T/S on. ??? When I tested the ground wire with the test light , I probed the ground with it connected to the Neg. battery side & nothing different happened which I though it would. I thought it would use the test light as an extra ground but nothing different happened????... ? Any more ideas would help. I'll try any thing at this point.

This what I did on my 67 turn signal housings. Worked great.

Charles

[sport coupe]

Rex, before installing the new printed circuit board you might want to check something out. If the back feeding is not from the printed circuit board something else caused the circuit board to go bad. Disconnect the connector in back of the cluster and see if the turn signals work. I never tried that so it might not prove anything.

[BillyGoat73]

Rex, erratic turn signals are mostly grounding issues. Your '73 has a ground wire in the tail light harness that is common to all the rear light bulbs. It is grounded to the body with a screw near the trunk latch along with the ground wire for the gas tank sending unit. Check this for corrosion, clean it up, and add a small star washer between the body and the ring terminal on the ground wire for good contact.

The front harness is the same way, with a ground wire in the harness that is grounded via a screw to either the radiator support or the fender bracing (I'm at work right now and don't have my service manual handy).

The other ground to check is from the engine block to the firewall. This strap is how the body is grounded. The negative terminal from the battery is bolted to the left front of the engine. You need the jumper strap between the engine and the firewall for continuity. If the ground path is bad, all the lights will work erratically.

[rexs73gto]

Hey guys I found the problem. When I put the car back together about 7 years ago I had not rried any thing at that time but I connected the left side maker turn lamp wire to the groud & caused a back feed into the turn signals. I found it tonight with the help of some friends who stoped down who know I was having a problem. They helped me trace down the short & now all works except the side maker & I'm going to fix that tomarrow. That will be an easy fix now that I know what I did. Thanks for the help as it did give me some things for thought. You know the longer it takes to put them back together the more things you for get. I was the cause of my own problems. Now to find the ground for the head lamps as they are a bit dim, but again that shoukd be an easy fix to as if I can't find one I'll make a ground to fix it. Thanks for all the help. Rex.

[camerjeff]

Glad you got it sorted out!!!