Battery Drain

[rikbar]

hello everyone,
I have a 1986 pontiac grand prix 2+2 that has a battery drain problem. I have put a test light between the negative battery cable and post, pulled fused until the light went out. Found the doomlight fuse and the fuse marked CSTY-Clock seems to be causing the drain. Can someone tell me what is on the CSTY-Clock circuit?
or maybe something on that circuit that could be causing the problem?
I appreciate any help.
thanks
rik

 

[srercrcr]

Courtesy would be the underdash lights, if so equipped.

 

[SBCregal]

i'd guess courtesy light/clock...
if its the clock, it'll have a minor drain...to keep it running
grab a test light and see how much of a draw is there

 

[rikbar]

Thanks for the info, will check tonight. It does have the underdash lights, but seems like everything turns off when suppose to. I was thinking clock, but if it is working correctly, shouldn't drain battery overnight. Will keep looking, again thanks.

 

[jatguit]

I believe the ETR radio has a trickle charge for holding the preset stations there.
Also, isn't that were the ECM also takes a constant charge for it's memmory functions. I believe I just read this in the GM manual.

 

[dan2286]

The memory shouldnt drain the battery overnight, thats just normal operation.

Also, is the test light really dim? I dont think the memory will draw that much power, so if its bright it would be something besides ecm/radio memory. The glove box, trunk, and underhood lights are all in that same circuit also. Try taking out those bulbs and see if those solve the problem.

 

[jatguit]

Yes, it won't be much of a drain but, just want to make sure he knows there will be a drain in that location from hidden current draws.

I had a problem with my Bonneville and I ended up having to rebuild the alternator and that took care of it.
I have an idiot gage and it would on rare occasions flash(Mostly at startup), but not stay on.
So now it is fine.

 

[dan2286]

Yes, it won't be much of a drain but, just want to make sure he knows there will be a drain in that location from hidden current draws.

I had a problem with my Bonneville and I ended up having to rebuild the alternator and that took care of it.
I have an idiot gage and it would on rare occasions flash(Mostly at startup), but not stay on.
So now it is fine.

Good point. At least have the battery and alternator tested to make sure they are good, If everything looks good in that circuit.