gretzky99

so my Interstate MTP-91 goes out the other month & I think it's because I left my dash light on by accident...I'm gone for a week on biz last week & come back to deadness! again...charging now, if it drains again, what are my options...battery is only a yr 1/2 old...guy @ service station says it's not dead...needs charging..?? alternator ..yikes!!!

gretz99
91GT
thanks

Nicole

I had a similar problem on my '91 S4. The battery would go dead whenever the car was parked for a couple of days. I found that the switch for the engine compartment light was bad. If I pressed it down a little, the light would go off. If I'd press it down all the way, the light would come on again. Replaced the switch--problem gone...

Did I recently see your GT in Palo Alto on University Avene, parked in front of the BORDERS bookstore? Blue metallic with all grey interior and 'Techno' style wheels? I think it was on a weekday, and it was dark already.

DougM

Take the battery out, and bring it to an interstate dealer. They will run a load test, and depending on the warranty, they may give you a free one. I just did this last week and walked out with a brand new one. Car would be dead if sitting for 5 days. Interesting, my fuel pump does not buzz as loud with the new battery.

Moss928

When charging: be sure that the battery is either out of the car or unhooked. A new computer will put a hurtin on your check book!

Reinhardt

Had a similar sort of problem. Battery would drain after a few days of "rest". I noticed that the little light in the console ashtray would not always go out when I turned off the ignition.

Replacing the ignition switch fixed that. Just had the car stored (with battery connected) for four weeks and she fired right up when I got back.

I agree with Moss. Be VERY careful when you mess with the electrics/electronics. You could blow the entire harness. Not something you want for X-mas.

Trust me, I've been there!

gretzky99

took the battery to an Interstate Dealer & they said it was not dead, so they are charging it up & I'm gonna throw it in today...I'm thinkin it may be a drainer gremlin somewhere, but the electrical is pretty complex so I'm guessing! Funny, my under the hood light has never worked..maybe that's it Nicole..oh, not me in Palo Alto...we'll see soon

Jay Wellwood

Nicole-

I do not have access to the 91 eprints...but as I understand my 87 - in order to 'arm' the hood light - the park lights must be activated first (for safety motorist reasons as I understand it).

Is the hood light configured differently on the 91 model?

Just curious-

Nicole

Interesting... I checked it out, and it DOES come on with the parking lights off and no key in the ignition.

But I do know the light is different than in the previous model years. My '88 had this really primitive bulb, I believe towards the passenger side of the hood. The '91 has a real plastic housing in the center of the hood. Much nicer...

928 Brothers

Almost all 928s do this. Save your self the stress and intall a battery cut-off switch. If you don't drive your car everyday, this will fix the problem. Also, the DieHard international is ALOT better than the interstate one.

gretzky99

thanks 4 the info...how much for a battery cut off switch install? I found out the Interstate battery was defective...only holding a 56% charge after a recharge...had to pay pro-rated discount to get new one...haven't installed yet..

gretz99
91GT

John Struthers

gretz,
Bought the same Interstate mid July.
Started draining same week.
Checked door switches/red marker lights, o.k. Then every rocker light including hatch, o.k.. All dash, radio, ash tray lights, o.k.. Checked battery draw with ignition off, O.K. There is the alt. which checked out okay - one on the way though just to play it safe -, I think that the ground straps need replacing, cleaned twice. However, it's only a six mile run to work and I do use the sunroof a lot. I wonder if the poor batt. has a chance to re-charge? Pattycakes IS a daily driver and averages 300 to 400 miles a month. So, on with the new alt. a three day trickle charge - out of car - and new ground straps is the plan then on to the 928Bros batt. cut-off, as a last resort. Placed all rocker lights in the off position and disconnected radio last month... No Joy...
Let you know results.
later,
John S. & Pattycakes

dr bob

OK--

Got home (finally!) on Wednesday night last, got down to the other house where the 928 is living on Sunday, and she started right up after sitting more than six weeks. So it is possible to have a car that doesn't drain the battery (a NAPA battery in this case) when the car is stored.

To locate an electrical "leak", you can fab a quick-and-dirty tester by soldering a pair of wires between an old fuse (blown) and a small 12V light bulb. The smaller the bulb the better I guess, so choose a 211 or something similar.

Plug the fuse into each fuseholder and see which circuit is drawing current. You'll want to take the door switch closed while you test each position with your new "tester". The light illuminates when there's current flowing, plain and simple. Small leaks will not be very bright, larger will go to full bright.

Similarly, you can install the bulb in series with the battery ground strap as you are hunting. Add leads long enough to reach to where you can see the bulb. Pull and replace fuses one by one until the light goes out, plain and simple.