Just wanted to thank BC and its wonderful “search” function, as well as past and present gearheads (most of whom didn’t even know they were helping) for helping me through a recent electrical issue. Special thanks to Billboost37 for the direct help (and words of motivation
) and to Archon, markwb, Technical Ted, bill buttermore, toasted oats, and lash for their wonderful descriptions and processes in past posts. Although I have some pretty decent knowledge and the ability to sort through the FSMs and find fuses and circuits that could cause issues, I had never chased down a parasitic battery drain before on one of my own cars. Also, nothing electrically in my car was acting funny or unusual recently so I was going at it blind.
The rest of this is a LONG read. Really nothing new below, that already isn’t on BC in various threads, but I wanted to share my recent battery/electrical experience with the club. For those interested in; 1) Parasitic battery drains, 2) Whether a ’95 7-band CD player is compatible with a ’97 Bose system (or maybe the 7-band was just failing), or 3) Just interested in my story…..you may want to read on.
I left my office to go home this last Wednesday, only to find the Bonne wouldn’t start. Not enough juice to crank. I already knew I had a questionable connection from my positive cable to the positive terminal on the battery and figured that repositioning it and retightening might be the issue, but that didn’t help. Got a jump from someone at work and proceeded straight to Autozone, since my Duralast only had about 1 ½ years on it and my alternator appears to be original. Got to autozone and battery was reading 12.56v with the car off. While running, the alternator was putting out 13.65v and battery showed 13.55. So, I still figure that my battery cable was the issue and the reconnection and drive to AZ had recharged the battery and everything was fixed.
Wrong. Thursday morning, no crank, again.
I measure the volts with the digital multi-meter (DMM) and see the battery is 10.42v. Hop on the bus to go to work and plan on taking the battery back to AZ to get it charged up and a test load done on it while it is out of the car after I get home.
After work, I take the battery out and head back to AZ. They charge it to 12.43 and load tests prove good. I am convinced that the battery is still suspect, so I leave it out of the car so I can take a reading the next morning.
Friday, A.M., the DMM shows 12.42v….oh, crap (#1).
That means that only while it is in the car is the battery getting drawn down….and the thought of chasing a drain enters my thought process. Oh, well…back on the bus and off to work.
During my lunch break, I logged onto BC and type “battery+drain” into the search function. I began reading and researching and find some very excellent information and write-ups on parasitic draining as well as some other things I was already planning to try. I get home from work, change into the “work-on–the car” clothes and jump right in. Check the battery, again….12.41v. Still good. I inspect the negative cable and it is super clean (like new) and double-check the battery water level (it doesn’t need any water). I put the battery back in the car and fire it up to charge up the battery and for some “terminal-to-cable end” testing to make sure my charging system is functional. With the car running, I use the DMM to measure volts at the other points on the ends of each battery cable that connect to various components/grounds. Some minor loss of volts at the other ends of the positive cable (about .13 v), but nothing unexpected or irrational. So, despite my positive cable being a little chewed up at the terminal connection, both cables test out ok (although new cables have been ordered and should be here Tuesday
I then checked to make sure that the interior glove box light and trunk light switches were functioning to insure neither of those lamps were remaining on because of a bad switch and checked to make sure a cigarette lighter was not stuck in a socket….nope…those are all ok. I shut off the car and reached in to take out the keys (all windows are open), and let the retained accessory power (RAP) system shut itself down like it is supposed to do. I looked to make sure that the interior lights and radio have shut off and try to determine that nothing is on after the RAP rundown time (nothing was). I had also opened my trunk pass-through to make sure the trunk light was not on (and it wasn’t) and peeked into the glovebox to see that the glovebox light wasn’t on (and it wasn’t)….oh, crap (#2).
Up to this point, I had diluted myself and was still secretly hoping I didn’t have to search for electrical gremlins and was wishing for the “easy” find-and-fix that we all do when we have an issue). So, I now concluded that there indeed must be a parasitic drain, but before beginning the procedures I had found on BC, I once again started up the car. This time to allow the components that use battery power when the car is “off”, to “recharge” themselves (clock, radio presets, other memory type functions and settings). Apparently, this is done so when you hook up your DMM, your meter doesn’t act as a conduit, in series, and the components end up charging themselves through the DMM which could damage the meter.
So, I disconnect the negative battery, set the meter on 10 amps (10A) and proceed to touch the leads to the negative terminal and the negative cable. After some bouncing around, the meter settles at 0.38 or 380 milliamps (mA)
. Now, our batteries are supposed to have a maximum draw of 30 mA or .03A, so this is WAY to high. I decided to take another reading and I get 0.43 before the meter suddenly shows “0000”. Oops….oh, crap (#3).
I forgot that on my DMM you are supposed to wait 15 minutes between readings (and to also not leave the leads on the circuit for longer than 30 seconds at a time). The “0000” means that I have blown the fuse or harmed the internal circuitry for the meter to read amps. Oh, well, at least mA still works. So, I move the red lead over to the mA port and plug it in. Set the meter for mA and read again…..starts out with “OL” which means the reading is over the 400 mA maximum range of the meter, and settles in at about 364 IIRC. Definitely a parasitic draw.
So now I am depressed about having to pull fuses and possibly relays and as well as trace circuits, so I throw up my hands and decide to eat some dinner and figure that I’ll start the trouble shooting process in the morning (Saturday). :(
I had already been PMing and talking to Boost about my problem, so he knew of my testing. He calls me after dinner, I explain my results and he tells me to get my lazy butt off the couch, to stop whining and pissing and moaning and get out there and begin testing.
Begrudgingly, I comply.
He gets out his multi-meter and performs the same test on his car and gets something ridiculously low like 2.5 to 3 mA. I test mine again and it continues to hang around the 340-360+ range. We then begin to think….and like every good mechanic does, the first thought is always….any recent work done on the car? (although in my case, the question asked way too often is worded a little differently, as follows, “What did you touch, this time?”, implying that everything I touch on the Bonne automatically is suspect and has resulted in that component, now, probably broken or screwed up…thanks Bill
). We also begin thinking about the components that draw power when the car is off. From most recent to oldest, I installed ceramic brake pads and performance rotors a couple of weeks ago, last month I replaced the failed power antenna with one from an Olds 88 from the junkyard, before that was the installation of the custom homelink unit in the overhead console, and before that was the 7-band CD player from a ’95 Bonne…..hmmmm …you know….that 7-band always had a power surge that would be transmitted through the speakers every time I started the car. But the unit had been in the car for months with no issues and otherwise sounded amazing and was still working properly.
I pull the radio fuse (8d IIRC) in the driver’* side fuse panel and go put the DMM on again, still 643 mA. I crawl back under and start looking at other fuses. Hmmm….fuse 9d says Misc/RDO/Cluster. Bill does some research in his FSMs and it appears that the clock and maybe some other back-up/memory powered functions are on that fuse. I go pull it, and the DMM says 7.5 mA. AHA!!!!!!!!! Found the bastard. I disconnect the ’95 7-band and put the fuses back in and test again….still 7.5 mA. I put my original, stock ‘97, two band cd player back in and test again. 10.2 mA. Still well under the 30mA load. Excellent!!!!!!!!! Since then, all has been good, no electrical or battery issues at all.
Still don’t know if the 7-band went bad or was not compatible with the Bose system. I did have to pick out and relocate the orange power wire for the stock amp into a different pin on the ’97 connector. Power wire for the amp (and only wire in that connector) was on the opposite end of the connector in ‘95. Don’t know if the addition of a working/plugged-in power antenna had anything to do with it, but it was a recent repair that was electrical.
All-in-all I was dreading the worst, and got lucky stumbling onto the past radio swap and remembering the electrical “popping” power surge I had since the install. Again, there were no apparent visual or audible signs of any electrical troubles. The radio worked wonderfully and I never saw any lights flickering and never lost any memory settings on anything.
Thanks again, all, for your input, past and present, on the club. Even though I would have rather been doing just about anything else, you have once again, saved me money and I leaned a lot of really cool stuff in the process.