Alternator / Charging Help Needed!

[audiurq]

Just finished a timing job on my RS2, I had to have a mounting tab on the alternator
welded to repair it (must have been hit prior to my ownership). When running the voltmeter is railed at 16+ volts and the battery warning light is on. The battery
warning light goes out when at idle and comes on at anything above 1500 rpm.
When the warning light goes out the voltage drops to ~14 volts.

Anyway drove it 30 miles to work bad stop and go traffic, the car died going in to
the car park. The battery is extremely hot obviously it is getting over charged. Does
all this point to the regulator being toast, maybe whn the alternator mounting tab
was welded? Anyway to check.

I am suppose to drive it 8 hours to a car show in the States on Friday morning, all help getting it there appreciated.

thanks, Mike Hopton

[Trist28]

Does all this point to the regulator being toast, maybe whn the alternator mounting tab was welded?

Sounds spot on, when welded the surge prob blew the regulator - be careful driving it you could really f88k things up putting high voltages through the car electrics, at high revs it may push out 20+ Volts, or your battery may go pop!!

[johne]

The only consolation is that a replacement regulator & brush pack is cheap and easy to fit, you don't have to remove the alternator from the car.

There is a chance the rectifier diodes have blown as well, they are not part of the regulator pack and more integral to the alternator but they are also more robust and given you're getting voltage output I'd guess the diodes are still good.

John

[audiurq]

Thanks for the help. I left the car for an hour or so and the battery was still very hot. So I disconnected the +ve lead at the alternator and drove it 20 miles to a friend of mine who has an independent Audi/VW shop. I dropped the alternator and installed a new regulator, reinstalled but now only got 12V. So the alternator was toast, literally very hot toast. It was boilin' hot trying to get it off after only running for a minute or so. Now you try finding an RS2 alternator in Toronto, Canada on a Wednesday afternoon.... Bosch said it was a European only part number, imagine that. I ended up using parts from the original one and one off I think a 90 Coupe quattro, only 115amp At least it fixed the problem, although I think the battery is at best questionable at worst fubarred.... Still hoping to drive 8-9 hours to a car show in Carlisle, Pennsylvania on Friday morning.

[caterpillar]

the battery may bee toasted too. change it.. and get an 14.8v regulator.......and have the conecting cabel controlled..
if you disconeckt the cabel att the battery,when running the engine, you may frye the generator again.....

when weldin in the car or the exost... have the minus(-) cabel disconected...
when weldin in the car, have the earth from the weldin near the weldin point...