Fluctuating voltage....

[ozzie]

Chaps,

Hopefully a simple one... When driving at night I notice the my dashboard lights and headlights vary in brightness. This also corresponds with the power output of the car (97P 450), when bright the car is very aggressive and when dull (you guessed it!) less aggressive, (i assume it is the voltage regulator?)

What is the problem/solution?

Thanks in advance, Anthony

[shpub]

Bad earth connection on the front of the chassis. Bolt is under the rad and access is a pig. Sometimes can do it from the front. Piccies and details are in bible 2.

Steve
www.tvrbooks.co.uk

[incorrigible]

If that earth connection is on it's way out get it done ASAP, mine failed last year (I was shaking the car down after a rebuild) and the lights failed completely (they earthed through the windscreen wipers, which was amusing but not very practical)

You'll probably need to drain the coolant, but that's done regularly anyway (can't remember if it's 12k or 24k) Another thing not to pay for at the next service perhaps

[ozzie]

Chaps, Cleaned the earth very well... this has not helped... I still have the fluctuating voltage which can make the car 'kangaroo' at lowish rev's (c.2200 rpm). I have also checked the alternator output using the top of the rocket cover as an earth - this charges at tickover at 14v with 0.1v variation (i.e. not enough to display the problem).... Anyone anymore ideas?

Steve, you mention in your bible that there are 2 positive terminals that lead back to the battery from the alternator, one of which is part of the voltage regulation circuit. Mine is a 97P 450, what regulates the voltage? is it a component that I can replace?