xfspacsix

My younger brother just got his P's and bought an ED fairmont for his first car, and we have run into some trouble.

The car was driving fine when we parked at the supermarket but when we came out it wouldn't turn over, it was getting power and about 20 minutes of checking fuses and jiggling wires and it ended up starting, we were unable to pinpoint which wire or fuse it was or whether it was just coincidence that it started.
Now when he drives the battery light comes on and his volts drop to about 11, turn the car off and start it again and volts are fine (14 app.) and battery light turns off. All fuses in the car are fine what could be a possible cause of this?
The temperature gauge also reads very cold, I have yet to check thermostat.

useless

If power drops to 11 volts when driving it points to the alternator or belt.What is the voltage at standstill and off?Is the earth off the battery clean?

xfspacsix

It drops to 11 but turn it off and start driving again it will immediately jump straight back up, and the car starts very strong, terminals are clean and connections are very tight. I don't think the problem lies with the alternator or battery, I am leaning more towards the signal displayed on the dash is incorrect. I also believe his fuel gauge can give innaccurate readings.

MLS

Sounds like it could be the regulator for the alternator.

xfspacsix

would the regulator being faulty cause the dash gauge to read incorrect voltage? (sorry have no idea)

Mike Gayner

The dash guage is fine. Definately an alternator problem, but it's not the regulator. Could be the belt, but if it's not making any noise that's unlikely. Check the terminals on the alternator. If all else fails, pull the alternator off the car and check the brushes (easier than it sounds).

xfspacsix

I really don't think it is the alternator as the car has been driven a lot and start-up is strong, it can be run with lights and stereo and doesn't miss a beat, my old xf had alternator probs and a week of driving straight off the battery and it needed charging again, so I am 99% sure the alternator is not to blame.

lilMattie

Possibly might be a short as well. My parents had some similar problems with their fairlane. Several alternators and batteries later it ended up being an electrical short in the power windows in the driver door... Nasty beggar to find. We only found it when we were cleaning it up to sell. - which we did. Poor old girl was stolen once, and was never the same after those punks joyride.

All the best, hope you find out what it is.

Matt

__________________
I'll be outa siiiiiggghhhtttt...
When I get my wheels, I won't even wave goodbye!