Hi Guys,

I have a new-to-me 2001 Ranger XLT stepside with the 4.0L and I have a somewhat strange problem. When I mash the throttle to pass slower traffic, around 3200 RPM and onwards the battery light will start to come on and flicker, and my headlights will dim slightly. There doesn't seem to be a loss of engine power at all but I was wondering what could cause this?

I replaced the battery about 2 months ago as the old one was shot. Is this possibly an alternator issue or something more serious? No starting problems and no problems below 3200 RPM. Let me know what you think, thanks!

TheBishop

 

Could be your belt tensioner going out, or the belt slipping, but more than likely it's your alternator beginning to crap out.

 

Pull the alternator and have it tested.

It could be the brush springs are weak or the brushes are worn out. Also possible the voltage regulator is bad.

 

I think that will definitely be the next step... My tensioner also squeaks, has a wobbly bearing and is needing to be replaced so between the two of them I think that would be the issue. Makes sense too if the belt starts slipping at higher RPMs due to poor tension.

I'll give that a shot and see what happens, thanks for the idea!

 

Keep us updated.

I had a similar issue recently, and certain vibrations from different rpms wiggled one of my grounds loose.

 

You were probably about to go back in time. This is why I have such a light foot, I don't know if I could handle myself time traveling.

 

I had a 1998, had what I thought was an alternator go bad.
Opened the hood and the idler had almost fallen completely apart.

If you do a new alternator and getting the old one checked while out is a good idea, replace the idler and the belt either way.
.

 

My Ranger (2008 XLT, 4.0L SOHC) did this to me last year and eventually turned out to be the Alternator. When hitting the onramp to most freeways, I would floor it and when it would get to around 5900 RPMs, it would dim the lights, cause loss of power, and the battery light would come on. Turned out the alternator was losing current for some reason with the internals. $300 later and I no longer have that issue. (and this happened after I replaced my battery as well)

 

Yup, well after taking my alternator to a local rebuilder he told me the regulator was bad and rebuilt the alternator for $100. After putting it back in the truck, i drove it for a few blocks and noticed the same issue. Frustrating. I took it back to the rebuilder and said "Hey, fix it! whatever you did didn't work." He looked a bit deeper and found a short in the 'fusible link' between the battery and the alternator. I honestly hadn't even heard of such a thing before and I'm a weekend wrencher who has rebuilt two engines on my own.

Regardless, he replaced a 15cm length of wire lead off the battery to the alternator and the problem is fixed. Only charged me $30 for his additional hour of diagnostics and searching. All in all a fair deal.

I also replaced the tensioner as the old one was squeaking and visibly worn.

Now to figure out if I need a new oil pump (on an unrelated issue) and then all my gremlins wil be gone :)

 

Glad that you got everything squared away. I would imagine that a bad alternator would cause "battery draw" problems. I guess I got lucky when my 04 4*4 light lit up. I went to Advance to have the system checked, and I was told that it was the alternator. Ford wanted almost $500 to do the work, and I was out-of-warranty. Also, I was told that Ford used two different outputs for my year 4*4, and naturally mine was the more expensive one. Anyway, I bought a remanufactured alternator from Autozone, and paid a buddy to swap the old one out.