johnfm

Obviously! Turn off the radio too etc etc

914und993

Check the glove box too. I had a small object jam near the hinge that apparently kept the door far enough from the switch that the light did not go off, and the battery drained.

Chip

Wil R. Ferch

Ian:
One more thing...unusual current draw was the basis for an article in Excellence magazine a few years back..and it went through the dealer problems of trying to find this. Early C2/C4's had a pinched wire in the basket that holds the radio in-place. If all else fails...check the radio by having it pulled out and check for localized wire chafing near the support cradle.
---Wil Ferch
PS- what did the power window / door button search find?

Ian A

Hi Wil

the car is currently in for some engine work - I will let you know of my findings as soon as I get it back and test it out

The radio that is in the car at the moment is not the original Blaupunkt system - does the above still apply?

Thanks for your help

Ian A

Wil R. Ferch

The article mentions a chaffe in the wire of the original loom that ws hard to find. I would sya that a replacement radio might similarly have this fault...if it exists originally...go unnoticed.
Check systematically....
--Wil Ferch

Fred, Long Island

Window rocker switches can go bad or sometimes barely stick in the 'On' position. I had one go bad and drain the battery. Unless you wiggled it and insured it was in the neutral position, it was difficult to detect visually.

Ian A

ok - update:

After trying all the methods described, I have tracked the problem down to fuse number 38 (Stereo, Booster). With this fuse removed, there is a significant reduction in the m-amps being drawn from the battery - from 2.21 to 0.03 - when using the "in-line multimeter" test.

No wires appear to be snagged, but could there be anything else other than the stereo and booster included on this circuit (installed at the factory as opposed to an after sale add-on, that is)?

Any thoughts appreciated before I begin the lengthy task of tracing the wiring!!

Ian

Ian A

mojorizing

Hi Ian,
Try this for the next level of troubleshooting:

Using the same method as before w/ meter but with fuse installed, remove and disconnect radio....check current load. If load is reduced, then radio is suspect. Disconnect wire to RF antenna amplifier (booster)....check if load reduced, etc. If same amps with radio/booster disconnected, it could be a chaffed lead a wire or some other device that a previous owner installed. I believe the booster should only be powered up when radio is "on", not all the time. Also all newer radios use a small amount of current to keep their memory. Hopefully, this will help in locating your gremlin.

Marc '91 C2 Coupe

Ian,

Welcome to the group, and welcome to the joys of Porsche ownership. I took the plunge a little over a year ago, and have been a very happy camper ever since.

When I first bought my car, I too had the dreaded dying battery problem. After changing the battery, a new Porsche friend mentioned he'd heard about the door plunger switch thing (as noted by Wil above), so we tried it. Sure enough, when the key was removed and the driver's door opened, the window continued to function (it shouldn't). I had the switch replaced, and the problem disappeared.

As others have noted, however, this fix may only work on North American cars.

Hope you get it sorted, I know how annoying it can be.

Best of luck,

Marc

andrew911

Ian- please let me know how you make out- I have the same problem, and have the stock radio/amp. I will be replacing the stereo and amp this spring, so I'm actually hoping that is what is causing my battery draw. I have heard that the original amps can be the cause of draw when they get old, and that may be your trouble spot...

Ian A

Hi Andrew - ok, will let you know. The problem is *definately* related to fuse 38 though - will disconnect the amp tomorrow and see if that stops the drain.

Will keep you informed

Ian

andrew911

Great- I'll check back to see what you find Ian!

Andrew

Ian A

Ok - this is what was the problem:

After following all the excellent advice from you guys, I narrowed it down to the stero/booster fuse (#38) as mentioned earlier. The actual fault was with the powered aerial - for some reason it had been wired to a permanent live feed! so it was effectively always drawing from the battery no matter what. I quickly wired it back to an ignition-only live feed and all is well!

Having done a general rewire and tidy-up, there appears to be only a miniscule draw on the battery and so I'm now a very happy owner

Thanks once again to everyone for your help!

Ian A

andrew911

Well, great to hear Ian!! Do you have a power antenna on 964's on "your side of the pond"? We have an antenna in the front windshield here in the US, and have for quite some time (I believe since some time in the 1980's 911's had the antenna in the windshield). Anyway, I will have my car in the shop in a few days, so hopefully they can find my power draw as well!

I don't mind keeping the car on the battery maintainer when its home and in the garage, but there are 1 or 2 weeks that we go on vacation and I have to leave the car parked outside (by no electrical outlets for a battery maintainer <img border="0" alt="[crying]" title="" src="graemlins/crying.gif" /> ), so hopefully I can resolve my issue as well.

Andrew

Ian A

Andrew - yup, the aerial is in the windscreen, and is powered. My problem was that whoever installed the stereo (prior to me buying the car) had attached the powered aerial to a PERMANENT live feed LOL!!! So it was constantly draining the battery - even when the car was not being used.

Anyways, to date the drain has gone

Good luck with yours Andrew - let me know how you get on!

Ian