Electrical Problem

[crossman]

A month or so ago, I posted a problem with my Explorer's voltage gauge needle climbing while driving on extended trips and the needle bouncing back and forth at idle. I thought that it was the alternator and so did others, so I put a new one in last weekend, but it didn't change anything. I did a voltage check at the lighter spot in the ashtray and it read 14.5 volts, which falls in between 14 and 15 volts, like my Haynes manual says. Is there anything else that could be causing this? I have also noticed that the needle bounces back and forth a lot more now and will do it just about all the time, no matter what RPMs I'm at. The dash and headlights also flicker most of the time like they do at low idle. Is there some other voltage regulator on my Ex. that might be bad or something else that could be bad? This is really starting to bug me and I don't want to end up frying my electrics because of it.

 

[Stephen S]

How old is your battery?? Could the battery be going, and causing the fluctuations? I'm not aware of an external voltage regulator on the Explorer (doesn't mean there isn't one though). Just an idea.

 

[Trapper14]

well I am almost 100% sure there is not external voltage rgulator, although the internal one is in the alternator so I don't see why that did't fix your problem.... could be the battery

 

[jimbo74]

maybe a bad guage or bad connection somewhere....

 

[mrboyle]

Check your grounds!

 

[crossman]

I think I'm gonna have to go through and see if I have a bad ground somewhere. The battery is only about 2 years old and works great, no trouble starting or anything. Are there any main grounds to start off checking or should I start from the battery and work my way through the engine compartment?

 

[Gumbus]

Crossman did you ever solve this problem? I have a '91 Explorer Sport that is doing the same thing. When I'm at idle the voltage gauge bounces around a little and the headlights seem to throb. As soon as I'm above 1000 RPM the problem goes away. Then at times when I turn the ignition off the voltage guage slams all the way to the left side of the gauge and the needle gets stuck. I have to thump the plastic cover to get the needle loose. I have had the alternator rebuilt and my battery seems fine. There is a voltage regulator on the passenger side firewall that I replaced that didn't change anything.

Is it a ground loop? Anyone know?