electrical problem

[bmishoe]

Hi,
A couple months ago, my wife had a problem with our Explorer where she started it and the voltage needle was down below normal. The turn signal wouldn't work but she got home fine. Didn't happen again until yesterday. Yesterday when it happened she called me. After she turned it off and back on it went away.

I got home early yesterday and took the alternator and battery to Autozone, they tested them and said they were fine. I put them both back on, started it up, and saw that the needle was on the very low end of the normal range. The turn signals wouldn't work, but the lights and the radio did. Cycled power and it was ok.

This morning she had to start it 3 times for it to be normal. She did mention though that even when it was below normal and the turn signal wouldn't work, that the wipers did (so that means, lights, radio, wipers all work when the signal doesn't).

I guess this points to a short in the wiring for the turn signals? What's the best way to track this down?

Thanks for the help!

 

[bam_bam1ca]

Don't discount the possibility of a sticking brush in the alternator. It may be fine one time, and not working the next. It can change with temperature and vibration. Just because it worked during the test at autozone, doesn't mean that it will work in the truck. Next time that it is low, take a volt meter and measure the voltage at the alternator and then directly at the terminal on the battery. It could also be an intermittent cable due to corrossion.

A month ago my truck had the same symptoms. Finally I got frustrated and put a new alternator in and the problem went away. When I go the time to take apart the old alternator I found one of the brushes was really sticky, and wouldn't push up and down under spring pressure as it should have.