Hi all, my battery light on my 2001 F-150 SuperCrew flashes when ever the truck goes into passing gear, I've replaced the battery and it still does it. When it was in the shop (Sears) they hooked it up to their test computer and could not find any fault.
Anyone have any ideas? I'm planning a trip to the beach this weekend and don't have time to leave it at the shop....

Thanks in advance

 

what happens at high RPM? Is it specific to a gear?

 

Only in passing gear does the light come on. As soon as it comes out of passing gear and the RPMs drop, the light goes out

 

I have a similar problem. What I have and what I have read, the battery light comes on at high RPM. Someone on a previous thread suggested alternator failure as the cause.

Chris

 

Quick test.

Put the odometer into HEC test mode.
http://www.mustangworld.com/ourpics/News/99hec.htm

Go to the section of the test for the battery levels.

Check the value of the readings when the battery light comes on when going into passing gear. it could be a slipping belt, causing a low voltage level, or the ALT is not regulating correctly, which would be an over voltage value.

If you are still running the stock belt, get rid of it, and get a goodyear gatorback belt.

That is the quick way to test what is happening with the charging system.

Good luck, let us know what happens.

 

That would be a alternator prob, not a battery problem, like sscully said probably the stock belt slipping or you got a charging system prob.