Lights and a/c dim until I rev?

David_Shaggy01

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So I have a 2008 ford ranger 2.3l 4cylinder.
I don’t know exactly how long it’s been doing this but I noticed one night in this past year, that upon initial start and idle, the headlights, all interior lights, (dash gauge, a/c knobs) are dim, as well as the a/c fans blowing weak/low speed even on high setting. I noticed it can be corrected by revving the engine a quick tap or two. Then it blows a/c normally, and the lights are at full brightness the whole time the truck remains on. Until it turns off and I have to do it again. I know it’s bad to rev an engine immediately at cold start but I also notice that starting down the road also corrects the brightness and ac fan speed. It’s almost as if it isn’t getting proper voltage/power. But I just installed a brand new optima red top 25 literally mid day today, and the alternator was just replaced within the last 1-2 years and was also brand new. Only thing I could think of, is the alternator plug. The clip that well… clips it into place once plugged in is broken off, and it just sits plugged into the alternator by pressure and feels kinda spongy like a brake pedal with a fluid leak. But it still stays on and doesn’t fall off. With the plug I’d just figured it was either power or no power. And plus it’s jammed in as far as I can push the plug anyway. Even with the clip, it can go in any further. I will admit I have led bulbs mixed with halogens. But the truck has been doing this since before then, and after replacing some halogens, the truck doesn’t act any differently. Same problem. So I know the leds aren’t to blame. Idk what to do. Kind of bummed me out that the battery wasn’t the issue. I knew the other battery was 5-7 years old, and the cell was bad so naturally it made sense to me. And it cut me deep when I started the truck with a brand new 290$ battery and it didn’t fix anything. Anyways there’s my problem. I already checked the grounds in the engine bay and they are almost perfect. A little dust here and there but it’s completely rust free and still has its original white body color inside. Did I forget some type of magic Gravy that I didn’t add to the biscuits or do I actually have a reason to be confused?
 

nixrox

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It is also probably a good idea to make sure ALL the ground wires between the engine, frame and body are not corroded.
There is a decent anti-corrosion compound made especially for electrical connections available at Home Depot
 

Vettepilot

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Make a new 10 gauge ground wire directly from the battery to a freshly cleaned spot on the engine.

Then run a new 10 gauge wire from the engine to the body.

If that doesn't work, it's time for a new, hopfully upgraded/high output, alternator.

Or--> you could always sell the Ford.

All joking aside, Fords are famous for electrical gremlins that are difficult to exorcise....

Vettepilot
 

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