HOT alternator wire ?
Thread Starter
Heel & Toe
Joined: Jul 2010
Posts: 20
Likes: 0
From: Logan IA
HOT alternator wire ?
Was going to drive the 2000 vette today and I noticed the idle was getting all crazy shortly after pulling out... dropping under 500rpm and jumping back up. Like the car wanted to die. The DIC showed the volts jumping around too. 12.7 - 13.9... all over the place.
Parked the car back in the garage and checked the wires to the battery and then to the alternator. The bolt to the red wire on the back of the alternator (the one with the black ridged tubing around it) was scorching hot. So hot I couldn't even finger tap it. I thought I burned hole right through my finger.
Any idea what would cause that bolt/wire to get that extremely hot.
EDIT: Went out to test the car again. Retightened connections. When I started the car I noticed the volts on the DIC started at 11.x and then slowly worked up to about 13.9 (normally, the DIC just starts out reading ~14.2-14.4) Then, any bit of pushing the brake, etc... caused the volts to drain .1 or .2... it also could not keep a steady idle. The alternator and battery are both only about a year old.
Parked the car back in the garage and checked the wires to the battery and then to the alternator. The bolt to the red wire on the back of the alternator (the one with the black ridged tubing around it) was scorching hot. So hot I couldn't even finger tap it. I thought I burned hole right through my finger.
Any idea what would cause that bolt/wire to get that extremely hot.
EDIT: Went out to test the car again. Retightened connections. When I started the car I noticed the volts on the DIC started at 11.x and then slowly worked up to about 13.9 (normally, the DIC just starts out reading ~14.2-14.4) Then, any bit of pushing the brake, etc... caused the volts to drain .1 or .2... it also could not keep a steady idle. The alternator and battery are both only about a year old.
Last edited by bphein1980; Apr 1, 2013 at 06:31 PM.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Anytime you have high resistance in a high amperage circuit it will create significant heat. Just like what makes your stove work. Your problem is most likely a bad connection at one end or the other. Probably at the alternator where it was hot. Don't just retighten, but remove the connection and clean it very well since the connection/issue may have created some deposits which can leave increased resistance. If doing this does not solve your problem let us know.
Melting Slicks
Joined: Jun 2012
Posts: 3,163
Likes: 6
From: Oceanside California
If its good now, then Im sure its fine to leave it be for now. But you may have corrosion inside the wires creating resistance as well. It might be time for new wires if this continues to be an issue.
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
It may not be over. C4 alternator failures were notorious for overheating at the positive (red) terminal. After literally replacing eight alternators I finally stripped back the insulation on the alternator hot lead and the copper wire was oxidized black. I stripped the hot lead back until I found bright copper and then spliced in a section of 4 gauge copper wire. I SOLDERED the splice connection and SOLDERED the ring connector that attached to the alternator. Don't just use the crimped connection.
Charlie
Charlie
