[thirdman]

I have a 1998 ZX2 that has just started doing odd things with the battery light. Starting last Saturday, the battery light will come on when running above 2000-ish RPMs. When crossing the 2k mark, the headlights and dashlights become noticeably brighter at the same instant the battery light comes on. The battery light behaves the same whether I have a lot of things running (stereo, headlights, etc), or nothing at all.

I had the battery tested and it showed as being in good shape. I drove a lot this weekend and the battery did not go flat.

Additional oddness: when idling, sometimes the RPMs drop below 1000, and then sometimes the engine will stall. This one I cannot consistently reproduce, but it's definitely something new. Outside of idle, the car seems to be running just fine.

Possibly related?: over the weekend, the fuse for my cigarette lighter blew, and the only thing I used it for was to charge my phone. I tested the USB thingy in a different vehicle, and it works fine. It was working before the battery light thing started happening, and for a while after the battery light thing started.

I promise I did search the forums before posting this, and the closest behavior I found was:
https://www.feoa.net/threads/02-zx2-battery-light-issue.72867/

I was not able to have the alternator tested yet, but that's my next step.
Any thoughts?

 

[marclar]

alternator voltage regulator is failing causing voltage spikes upwards, and causing excessive draw on engine at low rpm causing engine to stall...

replace your alt, dont buy a cheap autozone crap part

 

[thirdman]

replace your alt, don't buy a cheap autozone crap part

Gotcha.
Any preferred brands? Rockauto carries TYC, Pure Energy, Power Select, Motorcraft, AC Delco (new), and Pure Energy, AC Delco, Motorcraft, Remy and Denso (remanufactured).

The new AC Delco and Motorcraft seem to be the best bang-for-the-buck as far as the brands I have heard of before...

 

[FordMan59]

I had a problem with the battery light flickering off/on in one of my Escorts several years ago. The resolution to the problem was a new $5. set of brushes.

 

[thirdman]

The resolution to the problem was a new $5. set of brushes.

Really? That's a pretty small gamble. How hard are they to install?

 

[marclar]

delco, motocraft, denso are preferred.

 

[FordMan59]

Really? That's a pretty small gamble. How hard are they to install?

I've never replaced the brushes on a later model Escort but it was a really simple job on the 1st generation as I recall. If you have a Haynes, Chilton's or factory service manual it probably has the information you need. The lights getting brighter when the battery light comes on does sound like an a problem with the voltage regulator.

 

[Joey_Twowagons]

I have recently had my alternator apart to change bearings, and can attest that changing brushes is easy once the alternator is apart. It is probably possible to remove the back half without removing the pulley, which is the most difficult step.

I prefer to get stock alternators for my family fleet as well as friends' at a local Auto-Electric rebuilder, he's been around decades and has an excellent reputation.
I believe rebuilding the original alternator locally will result in a better quality part than a cheap aftermarket, or foreign rebuilt part.

 

[zzyzzx]

Check the brushes.

 

[FordMan59]

It appears some brushes are even cheaper than I remembered. https://www.autozone.com/batteries-starting-and-charging/alternator-brush/ford/escort The '88 Pony I drove for years still had the original alternator when I quit driving it at 518K miles and the only thing that was ever done was one set of brushes.

 

[Joey_Twowagons]

I recall many years ago visiting the local Ford dealer parts department and being told that they no longer were carrying small items like this, as they weren't worth their time.

It was only a dollar or two for brushes for early style alternators back then.

Happily ebay and aftermarket parts stores still carry them.

 

[zzyzzx]

Happily ebay and aftermarket parts stores still carry them.

Place like Advance auto and Autozone and NAPA carry them. Most will not stock though.