Did I just fry my alternator??

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Mar 1, 2011
Messages
879
Reaction score
133
Location
Australia
My Car
1972 Sprint Sportsroof
Had to jump start one of my daily driver cars (1999 Falcon Ute, battery dead flat) so that I could get the Mustang out for a drive.

So I ran the jumper leads from my Mustang, while it was running, to my Falcon. Well the Falcon wouldn't turn over at all, just various clicking noises and such, so I came to the realization that I needed to hook the Falcon up to a battery charger and get at least some charge into it before jump starting.

So after half an hour on the charger I hooked up the jumpers again from the stang and this time the Falcon roared to life.

Went back to the Mustang and noticed the volt gauge showing low, so check the stang's battery with a voltmeter while it was running and sure enough I am only getting 11.89 volts across the terminals.

Immediately thought that I've wrecked the regulator so swapped it out with a brand new solid state one that I had lying around, still no good.

The charge light on the dash goes out like it should, I've checked all my wiring to make sure no wires had come loose or broken and it all looks ok. It was running at about a 13.5 volt charge before the jumpstart episode.

So I'm at a loss, did I just wreck my alternator? Anybody got ideas as to what can go wrong during a jumpstart that would stop my stang from charging??

Thanks

 
Last edited by a moderator:
If you inadvertently invert the +/- cables, it will smoke an alternator, pronto.

Been there once :-/ .

 
Well, took my alternator and regulator/s to the auto elec who tested them and said they are ok and suggested I check the fuses. Before I bothered to check any fuses I put the alternator and regulator back into the car, started it and lo and behold the car is charging properly again! Can only think the problem was a bad connection perhaps.... :chin: still, I'm not complaining :)

 
Last edited by a moderator:
Glad to hear you got it sorted.

A few weeks back my alternator belt was getting noisy. Turns out it was misaligned and it's not a Ford alternator! Also when it was removed found a big crack on the underside of the casing. So this week fitting a nice new alternator from CJs and new wiring. I guess it was fitted back in the 70s when US Ford parts were hard to get hold of in the UK.

 
Back
Top