[240 BHP]

I've been experiencing the fun of having to remove the ground to the battery every time I leave the car lately, as I've got a 4.25 A drain from something that I just can't pinpoint. Had it into the local P car shop last week and they



Set up a multimeter and tested as every fuse and relay was removed - no change

Removed the only non-fused accessory I added - a subwoofer - no change

Pulled off the power cable to the alternator - no change

Removed the power accessory cables to the battery - the drain is gone



The battery's fine - and the alternator's charging at 13.85V. No mechanical noise going on, and seemingly all electric motors are working (cab top, seats, etc).



Any ideas on what direct wired accessory could be eating this kind of power?

Partial Post: Please Login or Register to read the full post.

[doster]

[quote name='240 BHP' post='33899' date='Apr 9 2007, 05:48 AM']I've been experiencing the fun of having to remove the ground to the battery every time I leave the car lately, as I've got a 4.25 A drain from something that I just can't pinpoint. Had it into the local P car shop last week and they



Set up a multimeter and tested as every fuse and relay was removed - no change

Removed the only non-fused accessory I added - a subwoofer - no change

Pulled off the power cable to the alternator - no change

Removed the power accessory cables to the battery - the drain is gone



The battery's fine - and the alternator's charging at 13.85V. No mechanical noise going on, and seemingly all electric motors are working (cab top, seats, etc).



Any ideas on what direct wired accessory could be eating this kind of power?[/quote]





Might try checking the courtesy lights, trunk, hood, glove box, they might be stuck on.



Good luck

Doug

Partial Post: Please Login or Register to read the full post.

[flash]

the first thing i would do is verify the battery - don't assume that it is ok, because it is new, worked before, or anything like that



check the specific gravity of the battery - have it load tested - batteries fail, usually due to a short between the plates - this is often caused by allowing the water level to get low, or using tap water in them, which contains minerals that then chain together and create a dead short

Partial Post: Please Login or Register to read the full post.

[240 BHP]

[quote name='flash' post='33919' date='Apr 9 2007, 01:24 PM']the first thing i would do is verify the battery - don't assume that it is ok, because it is new, worked before, or anything like that



check the specific gravity of the battery - have it load tested - batteries fail, usually due to a short between the plates - this is often caused by allowing the water level to get low, or using tap water in them, which contains minerals that then chain together and create a dead short[/quote]



Thanks for the advice.



All the lights were checked - in fact I removed the bulbs to be certain from trunk (cab), interior, glove box, and underhood. Also had the shop check out the 4 month old battery, and they say it tested fine. I'll call them to ask if they specifically tested what Flash mentioned. The issue only began 2 months after the battery was replaced. Shop's idea was that the starter or some other accessory, direct-wired electical motor had some issue and was drawing it down, even if not operating at all.



All ideas are welcomed, and if I get it figured, I'll post the final solution.

Partial Post: Please Login or Register to read the full post.

[Ryan]

Both my P cars draw the battery down for no apparent reason. If I disconnect the battery it will not show any discharge so I know it is not the battery. I have no idea what to tell you.

Partial Post: Please Login or Register to read the full post.

[240 BHP]

Yeah, it seems to be a common thing, especially with all the electronics in the later model year cars - but 4.25 Amps is a hefty load when nothing's supposed to be fully on. This is enough to mandate disconnection of the circuit even for a short break in use (a day or so)



Thanks

Partial Post: Please Login or Register to read the full post.

[S_Cal968]

Does the starter sound o-k upon start up? I'm wondering if the problem is with the soleniod or the wiring to it. At 4.2A the wire would feel warm.



Also, I recall some time ago a discussion having to do with the wire harness that runs down to the starter. At some point the insulation wears thin and a short develops.

Good Luck...

Partial Post: Please Login or Register to read the full post.

[240 BHP]

Thanks...starter sounds ok, but it's worth a touch to the wire to see.



Thanks for the suggestion

Partial Post: Please Login or Register to read the full post.

[Anchorman]

The harness to the starter can deteriorate to the point of having a lot of bare copper exposed. Luckily, I had decided to replace all of the power cables just for the heck of it and found the bad wires before any shorting problems developed.



The car does not have any inherent power drains. I just returned from a week in Europe with the car being untouched while I was away. I got in and it cranked and started as well as if I'd used it earlier in the day. So, if you're being drained, something is amiss.

Partial Post: Please Login or Register to read the full post.

[DAK]

I had a similar problem in that the batt was going dead for no apparent reason, I couldn't verify a substantial parasite drain with 2 different multimeters. I replaced the batt and it drained down too. So I replaced the voltage regulator, even though it seemed to be charging just fine according to the multimeter, and what do you know that fixed it. I commonly leave my car sit for a week or more and it never gives me any trouble now.

Partial Post: Please Login or Register to read the full post.

[huskydog]

I have the same problem. Car is in repair shop now. The battery drain was caused by the front hood light. Apparently it is part of the alarm system. When I put a bulb in and closed the hood the light would stay on. Foolishly I thought removing the bulb would stop the drain....wrong. You might want to check that. Also my car had a hard wired phone at one time that the previous owner just cut the wires and buried them under the dash. Not sure if that was a drain or not, but all of that wiring was removed too.



My drain was not that significant so it was hard to diagnose, but you can also try this. Remove the negative battery terminal. Put a miltimeter between the negative cable and the battery terminal, then start pulling fuses one at a time to see if the meter registers any kind of a change. It might help you isolate the problem.

Partial Post: Please Login or Register to read the full post.

[Kim]

There is a wiring loom that is attached (clipped) to the drivers side hood hinge. On my car the constant opening and closing had chafed the wires from within due to age. Three were cracked to the point of grounding. What I did notice was that the fan stayed on when the hood was closed even if the key was removed. I discovered this by simply wiggling some of these wires and hearing a snapping sound from a relay in the fuse box. Take a look at that. Once I had the wires repaired the problem went away. You won't notice it from in the car if the fan is left on low as it is rather quiet.

Partial Post: Please Login or Register to read the full post.

[Ryan]

Both my cars drain with the hood up and no fan is on. There are no bulbs in my under hood sockets. I don't see how there could be drain from a socket with no bulb to draw current.

Partial Post: Please Login or Register to read the full post.

[flash]

interesting on the hood - hadn't thought about it, but it might somehow be alarm related

Partial Post: Please Login or Register to read the full post.

[unknown4u]

Does your car have electric heated seats??



I did have a same strange problem that I couldn't find.

Because look in to the wiring diagram and see for yourselves that it is designed rarely!



If the wires are not correct one of the buttons stick, and the battery drains quickly as the ignition is off.



Try to remove fuse number 6 and look what the amps are.

Partial Post: Please Login or Register to read the full post.

[wingers]

Long shot, the altenator could maybe have a diode that has failed.

This can then let the current flow in the wrong direction when the systems are switched off.

Partial Post: Please Login or Register to read the full post.

[Todd951968]

Like HUSKYDOG, I too had the similar problem several years ago, of a drained battery due to the alarm wiring under the hood, which also caused the hood light to stay on. Taking the bulb out didn't cure the problem. I took it to the dealer and they disconnected the hood alarm circuit.

Partial Post: Please Login or Register to read the full post.

[Ryan]

So even if the alarm is not turned on, the thing can still draw current?



My 968 was converted to a Clifford system...my 944S has the factory unit and I don't think I have ever used it.

Partial Post: Please Login or Register to read the full post.

[240 BHP]

Thanks to all suggestions....I've not had time lately to play investigator, but as I said, every fuse and relay was pulled, and the 4.2 A drain stuck around, so that eliminates alot of first round guesses right there. That's also why the theory evolved to point to one of the direct wired accessories. Also, curiously, no noise is being made when everything's off (key out) so it's not an electric motor, unless it's one that's seized, but still drawing power. I'm going to take it back to my shop and give them some of the suggestions you guys provided, most notably the failed altenator diode, starter harness cables, voltage regulator, and the harness on the hood hinge.



Thanks again

Partial Post: Please Login or Register to read the full post.