Voltage Drop When Hot

[800Days]

I suspect the alternator (again).

The batteries where replaced about 9 months ago in Russia and have both been holding the correct charge (although one has always been about .3v higher than the other).

The car had the alternator bushes replaced in Morocco about 3 months ago. The alternator has worked fine since but has not given out quite as good performance as it did, but still worked fine.

The car has been parked up for 5 days without any use. I jumped in, it started fine and I drove about 5 miles and then all the 'idiot lights' came on and off intermittently. I could see from the dash voltmeter that this coincided with a voltage drop. The longer I drove the more they stayed on.

I've checked the system through, the earths look good, I suspecting slipping belts so I Changed them as I had spares with me. The batteries are holding charge and all connections are clean.

Again, when cold, the system seems to work fine giving out a good +14v straight after starting and then when it reaches temperature all the warning lights come on again and the voltage drops.

Any ideas.

[NiftyNev]

Is your harmonic balancer ok and not slipping? If it's ok they I suspect faulty alternator.

Nev.

[800Days]

Thanks Nev, I've got the alternator out and in bits so access to the harmonic balancer is easier. I'll check it this morning (not that I know how - God bless the internet). One of the brush springs in the alternator was a bit sticky and not pushing the brush against the spindle which I suspect might have been the problem! I'm going to check the diodes this morning and anything else I can with the voltmeter and put it all back together and hope for the best.

[800Days]

It was a problem with one of the brushes. The spring was a little sticky, I guess when it was getting hot something was expanding and stopping the electricity flow.

All working good now, with a +14v.

[NiftyNev]

Glad you got it sorted.

Nev.