Turn Signals

Rgpmalibu

Apprentice
Oct 7, 2020
93
33
Hi Gang,

I have a question about my turn signals and side marker lights on my '78 Malibu. I'll try to break this down as clearly as I see it.

1. Turn signals all flash, front and rear, when headlights are on or off.
2. When I turn the headlights on. the turn indicator on the dash comes on, on the right side only, as if I'm making a right turn, but the light stays on. This used to happen on both turn indicators, but one has since gone out when the headlights are on.
3. With the headlights on, when I go to make a right turn, the right hand dash indicator flashes like it should when you make a turn, and the turn signal flashes outside the car, but in opposite phase. When the dash light is on, the turn signal is off, and vice versa.
4. With the headlights on and the right side dash turn indicator light lit, the side marker light is off. It's fine on the drivers side. The right hand side marker light flashes like it should when the headlights are off.

It seems like that (with the headlights on) when the turn stalk is in the off position, I have power running through the dash, but as soon as the stalk is moved to make a right turn, power alternates from the dash to the turn bulb. Shouldn't power be running through that circuit at the same time, so that the dash indicator flashes in phase with the turn bulb?
Also, when power is running through the dash indicator, there is no power to the side marker light.

Could this be a ground problem? A bulb problem? I really don't know where to start checking, because I'm kind of a newbie with car electrics. Any advice would be well appreciated!!

And thanks in advance for helping me out. You guys are an awesome group of people!

Rob
 

ELCAM

G-Body Guru
Jun 19, 2021
804
93
I would look at the printed circuit on the back of the gauge cluster. The power for the dash illumination runs right next to the ground for the turn signal indicators. it the printed circuit has moved or shrank over time or the bayonet in light bulb socket is wrong from another application it could do some weird stuff.
 
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airboatgreg

Comic Book Super Hero
Oct 2, 2016
2,780
113
Ground each bulb with a jumper wire to ground. Start at the rear as that is most common
 
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79 USA 1

G-Body Guru
Sep 2, 2011
969
93
Cheektowaga, New York
Visually check all your bulbs, you may have one of the double filament bulbs that has a broken filament and has bridged across to the other circuit. While there as stated above...Check the grounds.
 
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