Another alternator one.....

roger · Post by **roger** » Tue Jun 06, 2006 9:55 am

Had my (911) alternator reconditioned about 500 miles ago and had to remove it recently to fit a new fan belt (pulley nut done up with air gun!). Once replaced all seemed well - healthy 14 volt charge on the voltmeter for a couple of hundred miles. I then noticed that the charge had dropped to 12 volts plus or minus 1/2 volt. I also noticed that the charging warning light was glowing dimly. On switching on the ignition I now get a faint charging light rather than the usual bright one. Revving the engine, or switching on lights, etc has no effect on the dim light.

Now... being as auto-electric conversant as Vlad the Impaler, I would welcome any thoughts from you electrotechnocrats. Thanks

Nige · Post by **Nige** » Tue Jun 06, 2006 10:11 am

make sure the regulator is earthed properly.

I removed my alternator 4-5 times and eventually had it rebuilt only to find the earth to the regulator was chuffed up. Bit of a clean up with some rough paper did the job.

roger · Post by **roger** » Tue Jun 06, 2006 10:16 am

Thanks Nige - now where's the regulator?

bjmullan · Post by **bjmullan** » Tue Jun 06, 2006 10:57 am

No sure where it is on a 914 but it's a small metal box about the size of two cigarette pack stuck together. Hope this help. And btw I agree that your problem is a bad earth.

Nige · Post by **Nige** » Tue Jun 06, 2006 11:35 am

should be hanging around the engine bay somewhere with 2-3 wires up its ass.

Mine's mounted on an ali cage in the engine bay to the left as you look at the engine (I think its in a similar place in a 914) the regulator was earthed to the cage, but the cage had 'whited' over on its mounting to the body so wasn't earthing properly istelf.

roger · Post by **roger** » Tue Jun 06, 2006 1:22 pm

Thanks guys - I'll see if I can find the aforementioned regulator!

middlefour1 · Post by **middlefour1** » Tue Jun 06, 2006 1:50 pm

Hi Roger,

It's on the relay board opposite side to the battery under the plastic cover.

roger · Post by **roger** » Tue Jun 06, 2006 2:40 pm

Ah - thanks Steve - I'll give it a once over. I suspect that its the lead that's at fault though - seeing as I only recently reconnected all the leads to the back of the alternator. (I hate taking that off!)

roger · Post by **roger** » Wed Jun 07, 2006 5:11 pm

Well - switched on the ignition and one very bright ignition light and 14 volt charge - mmmmmmm? Ran the engine for ten minutes, charge dropped to 13 volts and then to 12, but the ignition warning light stayed out. Gritted my teeth and removed the alternator - Voila, the smaller red lead had a broken insulator and the wire appeared to be touching the alternator body. I've checked each of the leads to the relay board with a meter and they're all fine. Do you techie guys think the dodgy wire could be the cause of my problems?

Nige · Post by **Nige** » Wed Jun 07, 2006 5:22 pm

dunno

have you checked the health of your battery?

roger · Post by **roger** » Wed Jun 07, 2006 6:08 pm

Absolutely brand spanking new and full of little charge thingies........