voltage problem

ovlov · 08-13-2003, 09:36 AM

my '86 944's voltage tends to get lower as it warms up. most of the time, i'll start up and it will stay perfectly horizontal (on the gauge) at 13 volts. then it eventually decreases. it will move to 12.5 next, then it will stay at 12.

is this normal? i dont think it is, but i could be wrong, obviously. i can definitely feel a loss of power between the times when i'll floor it at 13v and then at 12v, or even 12.5.

is this a problem with the voltage regulator? is the regulator external or easy to change on this age 944? could the battery just be old? its a recent purchase, so i'm still chasing small problems around the car, especially wiring ones. i'm thinking this could be part of the reason some of the electrics dont work.

SoCal Driver · SoCal Driver's Garage

Might be infected with nano-particles. These have a tendency to expand when the electrons get warm. Causes a marginal restriction. Need to tweak the phase inverters and re-align the nutrino matrix.

Get a new adjustable alternator regulator.

bearone2 · 08-13-2003, 10:26 AM

Does the alternator lite come on at the lower voltages? Does the alt lite come on when the key is on.

Silly question you say.
I had a Volvo problem years ago, the alternator lite didn't come on with the key on and the voltage was low when running. An older Volvo service rep said it was one of the goofiest things they had done electrically.
The alternator lite was in series with the elcctrical system and when it didn't work the alternator voltage was limited.

Don't know if Porsche is the same.

Have you confirmed the voltages with a separate voltmeter. Is the alternator belt tight enough?
Without a/c, the voltage should be in the upper thirteens at operating temp, idling
Have a high rate discharge/alternator test done on the battery/alternator if you can't do it yourself, checking the battery itself and the potential of the alternator. Could be an old battery.

ae1969 · 08-13-2003, 10:26 AM

hehehehe .... funny socal........

The voltage regulator is more than likely the culprit..... but also Check/Clean the grounds on these cars........... THEY ARE HORRIBLE.

SoCal Driver · SoCal Driver's Garage

The electrical warning light comes off of the alternator regulator. If the voltage is coming from the battery to the alternator then the light will illuminate. If the voltage is greater at the alternator the light will not illuminate.

Electrical grounds do need to be maintained.

ovlov · 08-13-2003, 01:43 PM

well. it dips to about 12 most of the time. i saw 11.9 on the way home from work, i might have had the a/c on, im not sure. no light comes on though. i've never seen the gauge go under 12, unless it was just barely under (like today).

i suspected the grounds also. ill clean them and check the belts once it cools down. ill also check the price on a voltage regulator.

i might just do a whole maintenance on the ignition system. it cranks a few times before it starts, and when i changed the plugs, i felt more of a difference than i should have.