Hey! I'm completely stumped on an electrical issue I'm having. I recently bought a '76 Monte Carlo and the turn signals aren't working properly.
So far I've:
• Replaced the flasher on the fuse panel (552 flasher)
• Replaced the multifunction switch in the column
• Checked/replaced all the 1157s in the taillights and the 194 marker bulbs

Here's what it's doing:
• Headlights, taillights and brake lights work fine
• After replacing the flasher on the fuse panel the hazard flashers work properly, and ONE of the dash blinkers (the right one) blinks.
• When I turn on the left or right turn signal nothing happens UNLESS I have the brakes applied...when the brake lights are on and I turn on the left blinker the left side brake light goes out, and when I apply the brakes and turn on the right blinker the right side brake light goes out.

My questions are:
• Is there a second flasher for the turn signal somewhere up under the dash that I'm missing? Some people I've talked to say the hazard flasher and turn signal flasher are the same, while some say there's another flasher under the dash somewhere.
• Based on what I've described above, anyone have any ideas of anything else that could be causing the problem?

Thanks for reading...appreciate any advice anyone can offer.
Curt

 

Hey Curt,
The wiring for the brakes runs through the turn signals. Sound like you might have a short, possibly in the brake light wiring to the back, or possibly the brake light switch itself under the dash. There might be another flasher under the dash, I kinda remember one on one of my older vehicles, but it might have been a pre-68 that didn't have 4 ways. It's been a long time since I had my 76, and I sure do miss it - I have a pic of it as the 'wallpaper' on my computer.

 

If you don't have a service manual, get one. If you don't have a multi-meter, get one.

Study the wiring diagram in the service manual to find all the items/lights that share the lighting circuits.

To track down electrical issues that aren't a priori obvious, you'll need to take the process of elimination approach.

The vast majority of electrical problems are due to poor/failed ground. As tedious as this sounds, disconnect grounds one-at-a-time, clean to bare metal, reconnect then dress them with dielectric grease. Doing this eliminates grounding issues.

Using the multi-meter, test the continuity of each light bulb in the marker/signal/brake light circuit; rear and front.
Using the meter, starting at the connectors that feed power to the column switch, test for current/voltage. Continue checking connections along the circuit all the while double checking grounds