phoneyman

I performed the current test by taking the negative lead off the battery and using a Fluke to check the current. Alarm/lock was activated and frunk was open but fuse 11 for interior lights was pulled so the lights were all off.

There was a spike at first contact to ~0.25A, then settled to ~0.10A. I've seen this number should be around 20 to 40 mA.

Are there any suggestions what could be drawing those extra 60mA to start hunting down?

Reasons for performing test:
- battery drains over about 7 days enough to not start car
- interior fans won't run by CCU controls
- Alarm lights flash quickly about 10 times when I lock the car and settle to normal flash
- durametrics cable has intermittent contact to car modules, but the one engine code was #108- voltage supply. Can't comm with CCU and airbag modules.

TIA

nine9six

This seems like the normal self test and alarm set sequencing that the LED's are supposed to give.

I am thinking there is some light in your car that stays on due to a micro switch that is bad or out of adjustment?

Check engine bay light, glove box light, frunk light and microswitch, door microswitches, engine bay light, interior lights...

Possibly the CCU is a separate issue?

phoneyman

I have the Tore led indicator lights and interior LEDs on the way, so I will check everything you mentioned. I did not think of the microswitches, thank you.

The reason for the part about the CCU is when my battery was very low a few months ago, the interior fans would not turn on until after 30 mins of driving. I assume because the alt. charged the battery enough.

I have never been able to comm via durametrics cable well, but that is something I will call them about directly.

BobbyT

The battery on my 993 would discharge prematurely when I left the car sitting for an extended period. I narrowed the cause down to the interior lights. I now leave them set in the "never on" position, which solved the premature discharge problem. I haven't taken the time to sort out the root cause with the interior lights.

pp000830

I don't know if your test is meaningful as when you disconnect the battery you probably change the state of the load as the computer becomes unpowered and maybe some relays as well.
First I would take you car to a battery place and have it starting load tested to make sure under normal operating conditions it has plenty of amperage capacity to begin with. Even brand new batteries can be in an unhealthy state right out of the box.
Having done this and found the battery to be good-to-go, I would go home use a volt meter across the battery or one of the type that goes in your cigarette lighter. With the car running the voltage should be 13.5 or > volts. When you turn the ignition off it should be at 12.5 volts or better. Then lock the car using the fob and see how long it take to drop below 12 Volts as at 12 Volts the battery only has a fraction of its starting amperage available. If it does not drop to 12 or below over night you problem may be a loose or bad battery cable or ground strap.

PS The Durametric connectivity is always problematic on the 993. It can take several tries especially if you are running your laptop on battery power. The air-bag module on my 993 can only be accessed through the 964 menu.

phoneyman

Thank you all for the comments. Looks like I have a Sunday date in the shop with the volt meter.

Neil Perry

Hi
I have tested my 993, with everything off, but car not locked the current drain is 18mA, that is .018Amps.
I did also close the latch in the luggage area, with the bonnet open to turn the luggage light off.
1997 Carrera C2

Steve Weiner-Rennsport Systems

Thats considered normal.

IXLR8

The 993 not being a CANBUS car, you can use the pulling of the fuses method to narrow it down to a system.

Of course as already mentioned, make sure all lights are out and the CCU fan is not the issue.

I hope it isn't a leaky diode in the alternator.

phoneyman

I hope it doesn't end up being that complex also. I've pulled a selection of fuses and checked all lights but the ashtray and glove box. Next will be more fuses and the aftermarket radio. Then deeper if needed.

Is it ok to leave my multimeter between the battery and ground strap for extended periods as I pull and disconnect things?

IXLR8

Yes, since you want to see the current drain go down to less than 50 milliamps.

You are on the 200 ma DC setting on your meter, I take it. Just make sure a light does not turn on while you are connected or you'll be replacing an internal fuse in the meter...most likely a 5x20 mm, ~500 mA fuse.

phoneyman

The Fluke I am using is auto sensing with a 10A fuse. Thanks for the advice. I think I should build one of those in-cab volt meters you have in yours.

pp000830

I have one of these.

Allen

A voltmeter isn't gonna help you with a current draw issue...

phoneyman

@pp : I like that solution for quick checks. Thanks for sharing.

@Allen : You are of course correct. I should have added I like the idea of a volt meter because I can get an idea if the battery discharges too quickly in the future. Itd be a nice indicator instead of just going out to the garage and it not starting.