1997 Mustang alternator not charging when cold
11-13-2016, 07:41 AM
#1
Thread Starter
Join Date: Nov 2016
Location: TN
Posts: 1
1997 Mustang alternator not charging when cold
I'm having an issue where the alternator isn't charging unless the outside temp is above 40deg or the engine heats up to operating temp.
I've replaced the battery and the alternator plus the connector going into the alternator and still have the same issue.
Voltage reads 11.6 volts when the car is running, when it starts charging it charges at over 14 volts.
Any idea what else I can check?
I've replaced the battery and the alternator plus the connector going into the alternator and still have the same issue.
Voltage reads 11.6 volts when the car is running, when it starts charging it charges at over 14 volts.
Any idea what else I can check?
11-13-2016, 09:02 AM
#2
4th Gear Member
Join Date: Mar 2010
Location: TN
Posts: 1,626
Could simply be the belt. In the cold they harden up and slip too. Id check that first for the easiest cheapest fix.
Other than that Id take a close look at that alternator. Ive said it many times before.....rebuilt alts are notorious for problems out the door. Id say at least 25% are bad. I got a new rebuilt one. 2 mechanics told me it tested as good but I kept having problems. I took it to my local guy who has done nothing but alts for 60 years nearly...since he was in high school. Had 2...2!!....bad diodes in it and really needed brushes. I let him repair it...cost maybe $30 IIRC....and it has worked perfect since that day. That was 2011 I think.
So if you have a alternator specialist or just a guy who works on them...try them. Let a pro test that thing. If the wiring is good, the battery good, and the alt good theres no reason for it not to work right.
Other than that Id take a close look at that alternator. Ive said it many times before.....rebuilt alts are notorious for problems out the door. Id say at least 25% are bad. I got a new rebuilt one. 2 mechanics told me it tested as good but I kept having problems. I took it to my local guy who has done nothing but alts for 60 years nearly...since he was in high school. Had 2...2!!....bad diodes in it and really needed brushes. I let him repair it...cost maybe $30 IIRC....and it has worked perfect since that day. That was 2011 I think.
So if you have a alternator specialist or just a guy who works on them...try them. Let a pro test that thing. If the wiring is good, the battery good, and the alt good theres no reason for it not to work right.