1986 944 Alternator

[Redline944]

My beloved car is sick and I could do with someone with a similar (early dash type) going out to their garage to check something for me.

When you switch the ignition on (without starting the engine) does the battery light illuminate?

I'll explain why. The car in question has been off the road for 12 weeks so the battery was flat. Charged the battery up and the car starts and runs fine but it would appear that the battery is not being charged by the alternator. So over the course of a drive of say 100 miles I watch the voltage reading gradually fall away to 9 or 10 volts and then the car stops.

But... if the alternator was sick I would expect the battery light to come on indicating a lack of charge from the alternator.

Hence my question about the light as it has been suggested to me that a blown bulb can actually take the alternator off line on some cars (not necessarily Porkers) and I would hate to replace the expensive bit when the 30p bulb would have sorted it.

Thanks in advance

[danww]

Happy to check mine tonight, but its later than yours I suspect - 1989 S2

Dan

[Redline944]

Thanks, The alternator is the same for 944, 928, 968 so any info will help.

[randlemarcus]

Has the alternator go pop on my 89 Turbo a few months back, and I can confirm that not only does the ammeter dribble away, but that the bl00dy great exclamation mark goes on, along with a battery low light. Most informative, really. Must admit, the DME antics when its run out of power are amusing(afterwards).
I have a spare alternator I bought off ebay at the time if you are desperate. My local garage did the whole lot for around the 200 mark including a recon unit.

Marcus

[hugh924]

I have been struggling with a charging problem for weeks- eventually traced it to a blown fuse that supplies the battery warning light - this meant no light on ignition, and thus no excitation of the alternator. Test the ignition light by disconnecting at the alternator and earthing it - it should come on. If the bulb has blown, most cars have a resistor wired in parallel to excite the alternator, so your battery should not go flat.

[danww]

OK I've checked my car. When I turn the ignition the alternator warning light (this is in the bottom red section of the voltmeter scale) comes on, it goes out when the engine is running.

Every other warning light (oil etc.) also goes out. All that's left is the exclamation mark and the "Parking Brake" light (in words).

Was this what you needed to know?

[Redline944]

Danww, thanks, that points to a bulb, definately

Hugh924, Fuse??? what fuse, I cant see a fuse in either of the two fuse boxes that it would relate to. Be grateful if you could get back to me.

randlemarcus, thanks for the offer. I will get back to you in a couple of days once I've pull the dash and replaced the bulb (and eliminated the 30p item). I reckon I saw the alternator on e-bay and got held up and didn't get a bid in!!

Thanks everybody for your input.

[basil brush]

It's a pretty standard alternator so you can get it rebuilt quite easily. I think I paid about 40 quid.