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[toobroketoretire]

The battery on my '82 has been going completely dead in one week so I have a steady drain somewhere. As my courtesy light timer was acting up (lights only dimming after one minute) I replaced the timer but that didn't solve the problem. Does anyone know the most likely sources of a small drain in an '82 are? I'm wondering if my ECM might be the cause but I'll know more after I get the battery charged and start pulling fuses.

I seem to remember working on my upper steering column a couple of years ago so now I'm wondering if my horn relay may be stuck in the ON position. So it's possible I put a part in wrong when I reassembled my horn button and associated parts. Even us old timers screw up now and then but as I'm getting older I am screwing up more often.

 

[KANE]

Here is a video that's pretty good... a lot of it is elementary and probably talks through some things you now, but it's pretty thorough.

Parasitic battery drain diagnosis- C4 Corvette - YouTube

The short story is to set up the voltmeter inline and to keep pulling fuses until the draw stops.

Hope that gives you some ideas for how to start chasing that parasitic loss down!

 

[toobroketoretire]

Thanks for the video but I already knew how to do all of that. I managed to get it started and the first thing I did was address my 1300 rpm in DRIVE fast idling problem. It turned out the top hose on my actuator relay valve had somehow come off so that was the source of the BIG vacuum leak. I got the hose pushed back on then reset the IAC motors so now it's idling at 750 rpm in DRIVE. I'll take it for a spin at over 30 mph tomorrow morning to reset the ECM and see if the idle speed drops to the usual 550 rpm in DRIVE. Then I'll dive into this annoying battery drain problem.

I have a feeling the drain may be in my horn button assembly because I think I had that apart a couple of years ago. Or maybe my horn relay is stuck ON and both of my horns are froze up from age. In the 28 years I have owned my '82 I can't recall ever blowing the horns because I feel it's an awfully rude thing to do over piddly things.

 

[toobroketoretire]

1/100th Of An Amp

I tested it this morning and found it was only drawing 1/100th of an amp after the courtesy lights turned off. As long as I start it every few days I don't have any trouble but after a week the battery will be too low to engage the starter solenoid. Tomorrow I'll see if I can determine which circuit the drain is on. A few weeks ago I pulled the 25 amp courtesy light fuse out and that didn't help.

 

[Antz81]

I tested it this morning and found it was only drawing 1/100th of an amp after the courtesy lights turned off. As long as I start it every few days I don't have any trouble but after a week the battery will be too low to engage the starter solenoid. Tomorrow I'll see if I can determine which circuit the drain is on. A few weeks ago I pulled the 25 amp courtesy light fuse out and that didn't help.

that doesn't sound like a large draw on the battery. I'm sure if I checked mine I would have similar results, but mine still starts after 2 months.
How old is the battery?

 

[toobroketoretire]

My battery is about a year old.

 

[SVO]

Bad diodes in the alternator will drain the battery

 

[toobroketoretire]

Drain Maybe Gone

Maybe it was the courtesy light delay module causing the drain because after replacing that module it sat for a whole week and started normally.