polarturbo

Hopefully you guys can help me diagnose the problem I encountered today. My 993 TT has around 25700 miles one it. Bot it in April (at 24700
miles). Today, when I drove it in the hot California weather (98 F), I
notice the electrical power is on and off few times for AC, radio and my radar
detector (via the cigarette lighter). Initially, I thought it was
battery and checked the voltage. It seems right (12.7V engine off and
13.8 V at idle).

When I was driving, I also see control panel lights (many of them)
suddenly on and off. Also, I felt the engine hipcup (no electrical power?) a few times when ever I turn on electrical stuff (like power down windows or sun roof). Pretty scary experience since I was not sure if I
would loose the power. So, I turned off AC, radio and unplug radar detector, the car is running smooth. At least, I got home safely.

Later on after I return home, I notice the right
front panel is extremely hot (hotter than usual), but the oil temp
gauge was showing quite normal (around 8PM direction). Can the oil cooler fan has anything to do with this electrical power problem?

I also notice it takes much longer to cool it down (engine
still hot after 4 hours). I did not drive hard though, just on highway
and local neiborhood.

Thanks for your help in advance.

ScottMellor

Has the wiring harness recall been done on your car?

polarturbo

Not sure. how do I check?

ScottMellor

Give a dealer your VIN and they can look it up.
Back when I had my '96, all my lights flashed and the car died once. I hied me to the dealer and they did the recall.

polarturbo

Ok. Dealer said no recall on my vehicle. Can this be ignition switch problem? Since the mileage is rather low (25K), I wonder would this be an issue?

911/Q45

Loose battery terminal?

ronnie993tt

You may wish to double check the recall by calling PCNA.....me no trust dealers. Both dealers here tried to tell my indy that my failed Porsche trickle charger never had a switch off function even though it worked fine for 6 months and the instruction sheet clearly indicated it did.

Felix

Check the battery connections very carefully to ensure they're clean and tight. It could also be an alternator issue. Has any work been done on the car recently?

polarturbo

Thanks guys for your help. Took the car to my mechanic and replaced 2 faulty fan resistors, ISE relay, and battery. So far so good.

Dealer said my 97 993TT was produced too late to need harness replacement.

Question: what's the symptoms if you have bad resistors and ISE relay?

Felix

ISE?

Turbodan

I think he is talking about the resistors for the fan for the oil cooler. if they are failing the fan does not come on. you can hear it up front right. Behind the headlight there is a resistor that if you remove it the fan should be on all the time when car is on (IIRC).
the switch at the oil cooler is a bitch to get to on my car as I have the extra oil cooler and the brake ducts...that was not fun the day I changed mine.

Turbodan

I think the elecrical issue is separate. did he check the battery connections and the alternator?

Felix

trying to understand what the ISE is... I wouldn't have predicted AC or oil cooling fan problems would cause running issues...

polarturbo

Sorry, it's the "15E" Relay