Problem with alternator
Thread Starter
4th Gear
Joined: Jan 2007
Posts: 4
Likes: 0
Problem with alternator
I recently rebuilt and installed a BB in my 69, ive got it running, but I can't get the new alternator to work. At the battery ive got 13.5 volts, but the terminals and alternator get really hot. Ive got 14.5 volts coming off the alternator which is what I want, but not at the battery. Im wondering if i wired it right, ive got a one wire alternator, so should I have just the wire at the post and the ground hooked up? Or should the plug at the top of the alternator? Or is the voltage regulator bad?
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
for sure somethings not right
on my 72 there is a red wire on the post, a black ground wire and then there is the plug all on the alt. This is serious and you don't need to mess around or you might fry the whole ignition, engine wire harness and front lighting harness... don't ask how I know.... but something isn't right and is causing a large build up, hence the hot terminals and alternator. Do you have an assembly manual? wiring schematics from like Docrebuild? you really need these as they are invaluable in this situation..... I would bet you have a ground off somewhere or even the polarity switched at some point. Either way fix it before it all goes up in smoke...
post some pics of close-ups of the alt and the horn relay... that's where all that wiring is based from in that area...someone with more knowledge on the 69 will chime in shortly.
best of luck,
Sully
post some pics of close-ups of the alt and the horn relay... that's where all that wiring is based from in that area...someone with more knowledge on the 69 will chime in shortly.
best of luck,
Sully
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
what Sully1882 said, and:
assuming that you are planning on driving your vette on the street, you'll want to install an alternator with the sensor wiring. lose the one-wire: sell to someone who really needs it. Go here:
http://madelectrical.com/
then go to electrical tech and read up on one wire vs three-wire alternators as well as anything else there on the subject. there are also some test procedures i think. consider the modifications to your car when selecting the alt capacity. lots of good info at that site.
btw, the voltage at the battery post will always be less than that at the alternator terminal.
assuming that you are planning on driving your vette on the street, you'll want to install an alternator with the sensor wiring. lose the one-wire: sell to someone who really needs it. Go here:
http://madelectrical.com/
then go to electrical tech and read up on one wire vs three-wire alternators as well as anything else there on the subject. there are also some test procedures i think. consider the modifications to your car when selecting the alt capacity. lots of good info at that site.
btw, the voltage at the battery post will always be less than that at the alternator terminal.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
1 wire alternators suck. The stock 3 wire is the way to go. But, if you want to run the 1 wire, connect the ground, should be a black wire to the case. Then the Big Red wire that goes to the BAT terminal on the alternator. The 2 wires in the connector that was on the side of the old alternator are for Field Excitation and Voltage Sensing for the regulator. The field exciter wire comes from the GEN light on the dash.
