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Baj
Monday 18th October 2010, 15:21
Last week I had flat batteries. I took out the alternator and changed the voltage regulator for a new one (not bosch, a copy)(how-to coming).
Car is running happily. No more flat batteries however the alternator is knocking out 16.5v.
Clearly this is wrong.
Why?
Dodgy batch of voltage regs?

Al115
Monday 18th October 2010, 15:33
Don't know, but I've heard that over-voltage can fry components in these cars quicker than you can say "OH SH*T". Best get it checked out soonest and not drive it until it's sorted IMHO. Good luck!

JUDGENINJA
Monday 18th October 2010, 16:37
sounds like it... should be kicking out 14.9V (is it 14.9????... It's so long I can't remember..)

Baj
Monday 18th October 2010, 16:39
14.5v

The general concensus is the reg is faulty. Supplier are ordering a new one.
I am just worried about what happens if that doesnt fix it!

JUDGENINJA
Monday 18th October 2010, 16:42
14.5v

The general concensus is the reg is faulty. Supplier are ordering a new one.
I am just worried about what happens if that doesnt fix it!

ahh... it's been a while... I must be getting old or something..

bubba_1986
Tuesday 19th October 2010, 20:30
The voltage can be regulated by using a Zener diode.

Ofcourse this is if the problem still occours

Baj
Wednesday 27th October 2010, 15:01
Hereforth lyeth a lesson:
After taking the car apart, getting a new voltage reg, rebuilding the car, testing the voltage reg, finding it duff, taking the car apart, getting a replacement new voltage reg, rebuilding the car, testing the voltage reg, finding it duff again showing 17v - I spoke to my father, an engineer of long pedigree.
"In engineering," he said "if things are not going as expected you need to start back at the basics with what you know. Test the battery with the meter and anything else with a known voltage. It is 99% likely that it is not the problem but it could be your multimeter is broken. We used to use analogue meters which stood up to electrical fluctuations and odd waveforms better than the digital ones do."
So I checked the battery without the engine running: 13.5v. A little high but not out of the realms of possibility.
I then checked the missus' 1.3 fiesta. Well I never. Her little 4 amp alternator is kicking out 16.5v (according to my meter)
I guess that would explain why my car is running fine and no bulbs had blown :/

frostytel
Wednesday 17th November 2010, 20:50
Hereforth lyeth a lesson:
After taking the car apart, getting a new voltage reg, rebuilding the car, testing the voltage reg, finding it duff, taking the car apart, getting a replacement new voltage reg, rebuilding the car, testing the voltage reg, finding it duff again showing 17v - I spoke to my father, an engineer of long pedigree.
"In engineering," he said "if things are not going as expected you need to start back at the basics with what you know. Test the battery with the meter and anything else with a known voltage. It is 99% likely that it is not the problem but it could be your multimeter is broken. We used to use analogue meters which stood up to electrical fluctuations and odd waveforms better than the digital ones do."
So I checked the battery without the engine running: 13.5v. A little high but not out of the realms of possibility.
I then checked the missus' 1.3 fiesta. Well I never. Her little 4 amp alternator is kicking out 16.5v (according to my meter)
I guess that would explain why my car is running fine and no bulbs had blown :/

That'll be a duff meter then lol ... get it calibrated