1987 NA.

I've read all the power drain threads in an attempt to isolate my problem. So far, I have done the following:

The other day, after sitting for 4 days, battery read 1 volt. Jumped the car, started up perfectly fine. Drove the car for 1 hour, shut it off, wouldn't start again.

This time, charged up the battery to full but still wouldn't start on her own. Jumped the car. Reading between posts 13.8 volts. Shut the car off, started immediately. Waited 15 minutes, battery now down to 11.65 volts.

Current draw with car off is 43 mA. Removed all fuses and only lost 6 mA with interior light and radio fuse removed (they were the only fuses that changed the reading on the meter). Doesn't seem like enough mA to drain that quickly.

Third new battery in six months. Brand new 1g battery cables and spotless grounds, though I have had this issue since about July 2011. New ref sensors and DME relay as well.

All factory and aftermarket alarms disengaged. At this power, starter will click but not turn over. And when you try to start a second time, you hear absolutely nothing. What could be drawing power or prohibiting this from starting? Have not ruled out alternator or starter, but blew all my money at this point on 87 951, so funds are tight - trying for the cheapest solution.

 

My 88 924S has a similar current drain problem, and I have given up trying to locate the source. I resorted to using a product called " Battery Brain". Google it and you'll find retailers and a better description than I give the following paragraph.

It is a remote controlled soleniod that mounts directly to the positive battery post. You simply activate it with the remote to complete the battery connection and use the remote to disconnect the battery after you park. THe only drawback for me is you lose your radio presets, but it beats going thru a battery every 6-8 months. Check different online retailers because prices range from $70 to $120.

 

Disconnect the battery, check for resistance from the positive terminal to the negative..

NOW

Disconnect the alternator, did the resistance reading change?

Disconnect the starter, did the reading change?

The disconnection that affected the reading is the internally shorted component... this could be caused by any number of things, most likely carbon tracing inside the component..

IF no major change, then disconnect the secondary busbar from your main positive distribution terminal.. this will isolate the central electric from your battery terminals.. if the short is in the central electric we can work through that to issolate the short, but more than likely it is in the starter or alternator..

 

Dave,
Like I said before, I've got a 951 starter that's sitting on the shelf that's a known-good part. If it fits you can have it for the cost of shipping.

 

43 mA is a lot of amps.....something is still on. Anything hot wired by any chance, sub, amp??

 

Nothing hot wired at all, no amplifiers or subs, . And .46 mA is well below standards, at least according to Clark's.

I've tried everything. Fully charged the battery, without connections, and it didn't lose a single bit of voltage in 24 hours. Alternator and starter tested out fine. I disconnected each separately and still the same draw. Car charges the battery fine while running.

I know I'm misssing something, I'm just not sure what. It's a head-scratcher for sure. Irony here is the car drove and started perfectly from last September until about July of this year. Parked the car for a very short period of time and it wouldn't re-start, and it hasn't been the same since this past July.

 

In the original post you have 43 mA and then in your last post you have .43mA. do you mean 40% of 1 single mA or .043A/ 43mA?
I work on Corvettes and anything over 20 mA is abnormal and will drain the battery in the matter of a couple hours.

 

.043A

 

I touched a Corvette once....Bruce