MJAKS462

1972 Cutlass convert.
I am putting it back together and dont have a left signal and flashers dont work.
I have replaced the 12v flasher on the harness by the steering column
replaced all bulbs
I can not get the left front side marker to light up all the way , it is just real dim like a toaster ? All other bulbs are lit up with the lights on . Right signal works fine . Do you suppose it is this socket ? I hate to hack the harness if that is not the problem.
Is there another flasher that I am not seeing ?
Thanks Guys
PS , parting a 72 supreme hardtop that had an engine fire , I bought it for parts.

Lady72nRob71

Sounds like a grounding issue. Make sure all black chassis ground wires are making good connection. Look partcularly at the ground that come from the left parking light socket. Paint, corrosion, and rust are good insulators. The battery sits next to where the ground wire should be attached, so look carefully.
If the ground is okay, the L parking light socket may need some close inspection.
Is the harness or the sockets new or original?
When the L turn signal is activated (running lights off), what happens? Rear bulb on?

The front side lights are wired in to the front turn signals (so they flash alternately), so there could easily be a common failure mode for both problems.

Since right signal works, signal flasher is fine.
Do you have a wiring diag? If not search here for "72 wiring diagram". I posted one a few times.

The separate 4-way flasher plugs into the fuse block.

MJAKS462

Tightened up some connections and now both front signals and markers blink with lights on or off but ,back driver side still does not blink at all , but running lights work so bulbs are good. ??????

Lady72nRob71

Remember that the bulbs with 2 brightness levels have two different filaments. Therefore it is possible that the running light part to work and the brighter signal part to not work.
If it is not the bulb, check the contacts in the socket for burning and pitting.
With the bulb out and the signal on (running lights off), check for 12V in the socket on just one of the contacts.

jeffreyalman

I love these threads. My 75 88 had issues with the right signal that actually went away all by itself. Sometimes the green indicator on the dash would come on dim with the lights, signalling me (no pun intended) that the RF turn signal was out. Parking light worked fine. New bulb, same thing. Then it stopped doing it and all works fine for a couple of years now. I chalked it up to a break in the wire that healed itself.

MJAKS462

Thanks Rob , I will check the socket and bulbs tommorrow. So do you think it is narrowed down to the rear driver side bulbs or sockets ? I wonder if that housing should have a seperate ground . I seem to remember a wire attached to the bumper from the housing when I took it apart ??? One other thing I notice is that when the lights are on, the driver side signal blinks slower than when they are off , passenger side is fine. I dont want to keep asking questions put I am pretty bad at electrical. I gave up on the signal earlier , and replaced all the dash bulbs and put seat belts in.

MN71W30

There is a ground screw up front on each side of the car right behind the headlights. It is a small screw and the wire comes from one of the headlight plugs.

jeffreyalman

what about MY advise?????

yzzerdd

Yeah, I've got the same basic problem on my car. Sometimes, the left parking light will be on, othertimes it is very dull and the dash light is dim. And then, there are times the dash light is fully illuminated, and no light at the left parking light. The turn signal seems to always be dull. Been meaning to swap the bulbs between the left and right, and see if the problem swaps over. Otherwise, guess when I need to get it inspected a year from now, I'll take it in when the light is fully illuminated.

--Ryan

jeffreyalman

my advise is ghostbusters.... just pay it no attention and it will go away I swear

I G N O R E I T

Lady72nRob71

The rear lights should have a seaparate ground wire(s). Check them out, too. Bad grounds cause havoc with auto electrical systems. If the front signal is bright and the back not, then we are isolating it to the back or worse the hazard switch. You might try turning it on and off and let me know what happens (if you put the flasher unit in.)
Asking ?'s is fine as that is how we fix stuff over the net. Electrical troubleshooting is a pain when done remotely. It would be much easier if the car was here.

I wish I had a nuclear accelerator to shoot all my troubles with!

MJAKS462

Front and rear grounds are good and tight
I put a new flasher in the fuse box , the hazards work
Still no blink in back driver side
Need to check bulbs today.
I have a push button start on the car , ignition wires from column are still hooked up , and there are 2 10 ga wires running from the push button through the firewall. It was like this when I got it and it works so I thought I would leave it. But I wonder if this has anything to do with the problem.

MJAKS462

The key has to be turned on before the button will work

Lady72nRob71

If the back tail (running) lights work and all the front and rear lights flash when the hazards are activated, then it is possible the turn signal switch is bad.
Make sure the hazard switch is pushed in all the way.
Do both of the brake lights work when you step on the brake?
Your push button starter switch should have nothing to do with the turn signal. Check for other hacked up wiring under the dash by the steery column.

Let me know what you find...

MJAKS462

Ok , I had my daughters boyfriend (Electrician) check it out and he found a bad connection on the plug just before the wires go through the hole in the trunk , now it all works , also had two bulbs in back that only one filement worked just like you thought. The signals do not slow down anymore either with the running lights on , the only thing I forgot to check is the brake lights , hopefully they work.
The harness all looks good under the dash , I found the lighter was unpluged because it is real touchy and you never no if it is on and heating up , so I just left it unplugged. may have to replace the lighter socket. Now I am trying to locate the plug for the switch on the shifter , I assume it is the Neutral safety switch . I found the plug for the console light under the dash but not for the switch. Also replaced the convertible top switch , hoses and fluid , now that all works.Thanks so very much for all your help. I am sure I will be back when I have my next problem ( By the way the switch is messed up in the column for the signals because I have to tweak the lever around to get them working on the left , hopefully that is not to hard to do , I am putting a grant wheel on any way .

Lady72nRob71

Glad I could help and more glad that you had someone who could check it for you in person.
Since you are replacing the steery wheel, you are almost there. Pull the lock plate and you should be home free. The service manual gives a nice procedure of it. Hope you have a manual on the way - best tool ever.

Sounds like you are making good progresss - keep it up! Post some pictures if you can for motivation to others!

Oh - i put in a request in your parts car thread...