Porsche Enthusiasts Club Forum

Could really do with some thoughts on the following;

When I bought my 968 project the battery wasn't charging, red light on the gauge was on accompanied by the ABS light.

So I took the alternator out and replaced the voltage regulator, the original bushes were very worn indeed. After charging the battery the car appeared to run fine with both the charge light and ABS light off and the gauge reading just over 12 volts.

I thought the problem was solved, however in recent weeks the voltage gauge seems to be getting lower, and today the car would not turnover due to a flat battery. After a jump start the car ran and gauge now shows 10 volts. With the car idling I have 9 volts across the battery, and 9 volts at the alternator on the large pin, and a tiny bit over 9 volts on the smaller pin.

The thing is, although the ABS light is now back on, and clearly I do not have 12 volts, the battery charge light has stayed off. I thought if the alternator was failing the charge light would come on.

Any thoughts gratefully received.

Is the wire connection at the back of the alternator ok? Mine wasn't, the car wasnt charging properly even with a new regulator, the charge light was out and the fault took some finding!!

Yup charge light & its connection is critical. Worth fitting new bulb & checking the connections to it. Or it could be a bad regulator. With the engine running & a multimeter across the output of the alternator then you should get close to 14V with a bit of throttle. The same across the battery. Also check the battery connections are tight with no volt drop to earth which isn't unknown on these.

I had a charging problem on my van that was simply solved by cleaning the alternator hot terminals and applying some conductive grease.

I got an internal adjustable (regulator) one from the states, there was a lot of chat on rennlist about how much better the car ran with 14.4 V at the battery, you simply replace the existing one with the adjustable one, and turn the screw on the back untill you get the 14.4V at the battery, engine runs better, lights brighter etc etc

Thanks all

I was starting to think this might be a connection / wire issue.

Chris, was the faulty wire on yours the larger or the smaller one?

I take it a break in the smaller wire would cause the charge light to go out?

Time to brush up on my continuity testing skills me thinks.

Thanks again

Ps -Keith, got the bits, your clutch pedal is now in situ-many thanks.

Hi

Have the battery tested for a dead cell..... 10 volts makes a battery very very dodgy...9 volts its drop in bin time......it should NOT drop that low for any reason....

All the best Brett

I echo bretts comments, give the battery a decent charge first. The car has been repeatedly started and is full of non conductive biscuit crumbs!

I have had alternators go bad previously and end up not showing the light. The light tends to come on when there is a difference between the alternator output voltage and the battery voltage. Sometimes (as I have seen before) regulators can simply go iffy over time.

A dead battery would not help matters, but the car should still charge. Where did you get the regulator from?

On mine it was both of them - the nut wasn't tight.

Thanks again for the input.

The voltage regulator was bought from GSF, made by Topran in Germany and stamped 14.5v.

A quick update - when the ignition is switched on as in position 2, all of the usual warning lights come on, but the charge light at the bottom of the voltmeter does not come on.

Have checked the terminals for tightness etc and all ok, have now removed both cables and pulled back the insulation of the smaller exciter wire cable and it looks fine.

Bit stumped now, must be a cable?

That is your issue! Check the bulb & holder

Thanks Jim

I will take a look.

looking at removing the cluster, is it essential to remove the steering wheel, I'm a little bit nervous about the airbag going off!

If you have an airbag, ironically the cluster will not go through the steering wheel.

If you do not have an air bag steering wheel, the cluster can slide through the top half of the wheel.

If you take the airbag off, and the steering wheel, disconnect the battery, put the airbag face down on the ground and don't hold it and a screwdriver at the same time.

Other than that, you should be fine.

But when you take off the steering wheel, behind it you will find a round object with a connector on it, do not mess with this and put the steering wheel back on exactly in the orientation you took it off in.