72442455

Hi all - first post - I have a 72 convertible - four ways work - left indicator works - right indicator does not blink - I've changed the flasher and it did not fix the problem - any ideas where I should start? Thanks all!

joe_padavano

Yeah, start by looking at the wiring diagram, which will show you that there is only one flasher for both RH and LH turn signals. If one side works, it's a waste of time and money to replace the flasher. By the way, did you replace the turn signal flasher or the four-way flasher? The one on the fuse box is the four way flasher. The turn signal flasher is under the dash on a pigtail.

Now, back to basics. The turn signals and brake lights use the same wires and bulb filaments. The tail lights are separate. Do the brake lights work on both sides, or not? When the turn signal does not flash, does the indicator light on the dash stay on? Have you verified that one of the turn signal bulbs isn't burned out?

stevengerard

As Joe mentioned check the bulbs, it may be a bad front or back turn single bulb as they have two filaments in them. I just bought a 72 Cutlass convertible and the wires for the lights have been a pain. The connects get loose and sometimes the parking light works sometimes it doesn't. Sometimes the turn signal works sometimes it doesn't. I have taken the wires apart and cleaned them and tried to get the connection firmer. When it gets a little warmer and drier out I'l take the harness off to do a better job. Hopefully you just have a bad bulb

Texas442

I know this sounds odd, but you may want to check the side markers bulbs and ground also.








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joe_padavano

Valid advice but that's not a 1972 wiring diagram. The diagram you posted shows that the side markers aren't even wired into the turn signal circuit, only the park light circuit. In 1972, the side markers actually DO flash with the turn signals, though they really won't prevent the lights from flashing even if they are burned out.

72442455

i did get the wiring diagram but I am new to a lot of this - I never knew there were two flashers so I thought I wasn't reading the diagram correctly - yes I needlessly replaced the four way *blush* and yes - one indicator light stays on - I will double check all the bulbs - it is possible that I missed one (using the glow of the fence to determine you have brake lights might not cover both upper and lower lights - but I believe they were all working - thanks for your reply I will start with that when I get out of work.

72442455

yeah - I believe my 72 side markers are turn signals as well - have to look into it when I get to it. I'm going to clean all contacts and check all bulbs - any one have a good sure fire way of cleaning up contacts like these?

Jamesbo

BTW

Welcome aboard. Hope ya get it figgered out

joe_padavano

One more subtlety in the wiring. The 1157 bulbs have two filaments, one for the brake/turn lights and one for the tail/park lights. These two filaments have a common ground point. If the ground on that socket is bad, the turn circuit will ground through the park/tail circuit. I've also had one filament break and short against the other one. At that point, all sorts of weird things can happen. Check the function of the brake lights with the park/tail lights both off and on.

72442455

thanks for all the great replies all! Unfortunately I have not had a chance to try these methods as I have had a much bigger issue occur 😕 I will post it in a new thread - thanks again

oldsguybry

Where might this 2 way flasher be located under the dash on a 72 CS ? Thanks

I meant the turn signal flasher , sorry

oldsguybry

Nevermind , I found it . That sucker was really hidden .

72442455

I was able to return to this issue and it is no longer an issue - I believe the cure for this issue was the fact that I had not reconnected the engine to firewall ground strap - after reconnecting that the gremlins lost interest. Thanks all!