1990 ranger 2.9L dimming lights

[jktruckin06]

Just picked this truck up. Runs ok. The lights will dim along with the voltage gauge dropping at idle and more so when lights and such are on.

With a slight punch to the fuel, the voltage rises, lights brighten then it falls on its face and picks back up to normal idle.

Checked voltages at the battery tonight. Battery was around 12.6x just running. With lights, radio, defroster and hazards on drops into 11s. Battery and alternator tested ok.

So what is you alls concensus? Start with the voltage regulator or alternator or just do both and be done with it.

Thanks guys.

[mustang_gt88]

I would have thought with truck running it should be at 13 plus

[Goober]

Does the voltage gauge go way up when the RPM goes up?

[jktruckin06]

It's real close Jeff. Goober, no it only goes to a little past the middle. It doesn't even have a temporary up swing, just straight to middle-ish.

[mustangjon]

Run it by the shop after you get of work i can test it for u

[Black Horse]

Check your engine to frame ground.

[jktruckin06]

Check your engine to frame ground.

Yeah I was reading some forums where they said to do this, I'll put it on the list. Thanks

I'll try to make it down for sure Jon

[Kevin1989]

I would have thought with truck running it should be at 13 plus

That's what I'm saying, when I worked in a shop most stuff would pull almost 14 while running and when it was 12. And lower we started looking for issues

[jktruckin06]

Did belts for now. Seemed to help a bit at idle but under accessory load still dims. Going to check the grounds tomorrow hopefully.