I have a problem with the turn signals and headlights. The turn signals work fine without the headlights on, then when you turn the headlights on the left turn signal works fine, but the right signals don't flash. The turn indicator in the dash and on the fender come on and stay on. Its similiar to when you have a burned out light bulb and the indicator stays on. The problem goes away when the headlights are turn off. Is the turn signal circuit run through the headlight switch? Or do I have the makings of an electrical gremlin?

this is on a 78 cordoba.

 

Im thinking it may be the turn signal switch. What happens when you put on the hazard flashers?

 

I had the reverse problem, no turn signals unless lights were on. It turned out to be a bad ground.

 

It could be either a ground in the forward harness or turn signal switch. Check grounds first.

 

I have the exact same problem as the original poster. Turn signals and emergency flashers work when my headlights are off.

But when I turn on the headlights, only the left turn signal works. Right turn signal and the emergency flashers act as though I have a burned out bulb somewhere.

I've read that this might be either the turn signal switch in the steering column or a ground on the forward part of the harness. I've done light repairs on my truck over the past 32 years, but those are two places I've not worked on.

Has anyone figured out what caused the problem for the guy who started this thread? Similar to the orginal poster, I own a 78, but mine is a Dodge Utiline.

Thanks in advance to all of you out there.

 

There is a part of the body just behind the grille on my truck called the radiator support. After re-reading the replies, I pulled out the wiring diagram for my truck and saw that there are a couple of lines terminating in an eyelet that provide ground for the right headlamp and turnsignal lamp.

During the summer, I had to replace the windshield washer motor which coincidentally used the same grounding point with it's own wire and eyelet. When I connected the ground back then, instead of putting the washer ground eyelet between the lamp eyelet and the radiator support, I put it on top of the lamp eyelet. With all the crud from the past 33 years, I now had a very poor ground. Doh!

Seeing this, I put the washer ground between the radiator support and the lamp eyelet as when the truck was manufactured. When I tightened the screw, the friction from the screwhead cleaned off the lamp eyelet. Now my right turn signal as well as my emergency flashers work again with the headlights on.

In California, we are required to have our headlights on during the day when it is raining. So due to my mistake, I ended up making this repair in the pouring rain.

Thanks to the guy who originally posted his problem as well as to those who offered suggestions about checking the ground. I hope that my detailed response will help someone else in the future.

 

Great post...thanks for taking the time to share.

 

I have seen more of these types of issues with the switch but check it all out before you dump money into another switch