Alt light on but Alt fine

[LowFlying720]

Hello

I got in my truck today and head out but as I pull away I notice that Alt light is on. So I stop and check to see if I lost the fan belt but it's still there and now when I start the engine the light goes out. Then as I'm driving down the road it comes on again.So I head for the local parts store that does free alt and batt testing and they both test out ok while the light is on. when I'm driving and the light comes on the temp and fuel gauges drop to to the bottom like power has been cut and the turn signals don't work, and when I turn on the turn signal the Alt light gets brighter. The headlights, wipers and everything else seems to work fine.

Ideas?

[petercscherer]

Could be a loose belt or tensioner-pulley.
~Peter

[LowFlying720]

Belt is tight and pulleys are solid.

Charging system and battery both tested fine with the Alt light on and I've driven it for over 2 hours with the headlights and the blower on and done several engine starts during that time. Battery is still charging and other than the gauges and the turn signal it's working normally.

[LowFlying720]

Someone suggested a loose ground but all the ones in the engine compartment look good. Is there somewhere else in the system that is grounded to look at?

[MrShawn305]

I have the exact same problem on my truck. The only difference being mine is not intermittent, it simply blows the fuse. If I replace the fuse they all work and then after a minute or two the fuse blows again and the gauges stop working. Just like yours, everything works except the turn signals, gauges and the bat light is on. I can drive it all day long as long as I don't shut it off and the alternator will keep running the electric fans, roll bar lights and everything else. Did you ever find out where your problem was? I did notice that it started happening to mine last night after I I had it pretty high sideways navigating some rocks. It didn't bottom out, scrape or anything like that, it just articulated a bit. Maybe something got pinched somewhere?

[LowFlying720]

No luck so far but the truck is not my daily driver so it's on the back burner while I'm putting out other fires.