DaveK

Well, you have to admit - failing to replace the alternator when it is broken is better than replacing the alternator when it's not broken!

Wachuko

Just a small break to wish Jim (jimq) a Happy Birthday!!!!

hawk911

started him a b-day wish thread, complete with girlie pic.

Richard Curtis

DaveK: Are you sure it isn't the battery? To check if alternator is charging the battery, start the car and have some hold the idle to 2,000 rpm while you check battery voltage. Should be around 14v. (sounds like your mechanic did that and got 13.5v, hence the alternator-okay diagnosis)

DaveK

I'm pretty sure it's not the battery for a couple of reasons. It's only 18 months old, and it charges absolutely fine on a trickle charger. I also don't think the battery would explain the other things I see - for example, the non-scientific test of switching the headlights on in the garage with the engine running - the lights don't get any brighter at all as revs increase from idle.

I guess it's possible the battery has had it and it's causing these problems - but I'll be surprised if it does turn out to be that.

ETA : Checked the voltage this morning on a recharged battery. At idle, voltage was about 12.5v. At 2k rpm, it only got to about 12.8v. It was also noticeable the car turned over much faster when it started than it did yesterday evening. The car will go back to the mechanic after work - and I'll get them to measure it while I'm there.