I came home today from work to discover my right front blinker on the Olds is blinking rapidly. No other lights were on. I said "wtf".

I had moved the car out of the garage as I needed to do some non car related projects over the weekend. Shut if off, locked it up etc. Was'nt blinking yesterday.

So I go to start it up and of course the battery is weak. I tried the blinkers, lights etc. They work, but a little weak. Right front blinker does'nt stop blinking even with ignition off or on.

I've removed the battery for charging and left the car in the driveway.

Where the heck should I start looking at first to diagnose this problem ? Flasher? or worse.....got other things to do.

 

If it's flashing i'd start at the flasher and work my way back.... but i dunno... thats strange

good luck,
Robert

 

The oddest thing here is it does it with the ignition off...

I almost thought it could be a short in the turn signal switch, but then only if the brake light switch was shorted also.
Do the wipers or radio work also when this fast blinking occures with ign off?
Can you hear the flasher clicking under the dash? Can you move the turn signal stalk and get it to stop?
Any signs of rodents underdash or underhood? It is getting cool and they have played havoc with my outdoor home wiring already...

When it is acting up, start pulling fuses to see where its power is coming from and we can trace it from there. I will try to remember to look at my wiring diagram when i get home.

As for the lights and starter being weak, after verifying the battery, check the battery cables and grounds, including the body grounds. The latter can cause strange problems in strange times...

 

Rob is correct, you have to have an un-switched source to cause this, either from the brake light circuit or a wire shorted to un-switched voltage someplace. Hope you find it.

 

Also look for pinched wiring under the hood and under the dash. I forgot to mention that earlier...

 

Maybe look into the hazard flasher circuit ... As this has power all the time.

 

Thanks for the suggestions so far. I'm a few days from digging into it, but it looks like the hazard/flasher system is a good place to start.

The car has led a pretty sheltered life and pampered some what. Except the drive train It gets a thrashing everytime its out.

Its probably something simple, I replaced one of the flashers about 15 years ago. I know they don't last for ever.....

 

I hate to say this, but check for mouse-chewed wires. I had a car parked outside for a while and mice had completely chewed through the wires to the MAP sensor.

 

I forgot about the hazard flasher circuit, good call. That off topic car I helped pick up two weekends ago had been chewed on by field mice. One spark plug wire in particular was quite evident and revealing as you could see the teeth marks on it, it had been chewed completely through. It was one of the larger 8mm wires in a bright (now faded) yellow color.

 

I thought of the hazzard flasher part myself last night; that will give a constant 12V to the turn signal switch, as long as the hazzard flasher is good (normally closed).

I would start by troubleshooting the TS switch.
Here is a photo of my 72's wiring; the 71 should be similar (I hope).

And while on the topic of rats, what do these critters find so irresistable about chewing on electic wires?
A norway rat got into an underground wiring pipe and chewed the high voltage cable and alarm feed wiring for my workshop in the back yard.
Now every time it rains, the central GFCI for the building trips and the main alarm goes off, triggered from all 3 sensors. I dread digging all that up. I set those sensors for silent alarm, so maybe now I at least have a rain detection service!
Stupid rodents... My neighbor had a whole nest of norways at the same time and has been at war killing them, with my help. At least I have seen no more signs of them.
Good luck on your flash of trouble!

... well, the picture is a bit small and unreadable. If you need the hi-res version, PM me and I will send it to ya.

 

I go with the hazard switch partially turned on or contacts dirty & sticking Larry

 

Bingo!

Larry, you got that right. The hazard switch...somehow was not quite all the way in or all the way out. I was poking around after looking at the service manual....all seems good now. I'll be keeping an eye on it.

Thanks again for all your input guys

 

Good to hear the news. Great.