On my way back to work last night i noticed that my volt guage was reading at 12v, the car felt really sluggish and used a heap of petrol to do a 80mile trip. When the car is sat at idle the reading is c.13.5 volts. I was driving with the lights on but this only usually drops the reading too 13v.

Any ideas of what could cause this?

 

Alternator on it's way out, old wiring breaking down, etc..

 

well i've not touched the altenator the only thing i have done is change the gearbox so had the starter motor out. before that it was running fine plenty of volts etc.

 

Most likely to be the battery to alternator cable degraded, check output from alternator itself to confirm it's ok.

Martin

 

Just noticed your other post make sure you have reconnected earth strap ok.

Martin

 

WOuld that have that effect on the car?

 

as there are two small wires coming off the starter motor could it be one of them as it seems to be draining the power as you accelerate.

 

Yes if the earth strap is not connected as this creates a good ground connection, I have heard of these wires before on starter motor, is one blue by any chance? but this almost certainly won't be your problem, still think it's an earth problem as it's only since you worked on it and IIRC these use the gearbox as a ground point.

Martin

 

yes the earth strap sounds like a good place to start, and also i like to add is just to give yourself a bit of a helping hand is to fit an extra earth strap from the battery to the gearbox caseing which will aid the dreaded hot start problems which plague a hot cvh, (you know the one where the car turns over slowly then starts fine when its cooled down)