My RX7 has 138,000 miles on the original altenator. I've been having problems
with the battery being to week to start the car after sitting a day. This is the
second battery I've had do this with less than 12000 miles on battery. This battery
was purchased May of 03 and is a DI-HARD GOLD.


My question is, when should the altenator be rebuilt for preventative maintance?

Thanks,

Brad

 

I pulled mine at 188,000 or so for "preventative" maintenance, but it was still doing its thing at that point. Consensus is about the 200,000 mile point for its life limit, some more, some less...

Grab a meter and read out the battery posts while idling. If she's over 13.5 or so, you're good to go as far as the alt is concerned. Any aftermarket items on the car (radio, lights, etc...) will be suspect for your battery drain problems, if that's what you have...

You also have an alternator warning light in the car, that will come on when the system falls below a certain voltage- have you seen it come on yet?

 

No, I haven't seen any idiot lights come on. The only change I've had is a head
light stuck up. The only thing I have after market is a radio, but it's wired to the
ignition.

I had Auto Zone run a test on the charging system and the store clerk said
the altenator was not up to parr. Then I drove across town to another auto
zone, they did a test and said all tested good.

 

Check to see if some circuit is drawing current when car off. Remove positive cable and place a meter between the post and cable to check if any draw. If excess found, start removing fuses to find problem. Check glove box light to be sure it's off when closed.

 

Thanks for the tip Tutbonut, will do.

Brad

 

If your headlight sticking up is not hitting the limit switches inside the motor assy to disable the circuit, that would explain your problems.

To troubleshoot, pull the 30A "retractor" fuse in the engine bay fuse box after shutdown, see if the conditions improve. Or you could accomplish this in conjunction with Turbonut's advice, testing to see if current draw is noticeably altered with that fuse pulled & inserted...

 

Alts can be run until they fail to put out enough voltage.

Most Japanese alts seem to last between 100K and 150K miles all dependent on load.

 

The light actually did not open one night and I had to open it manually from
under the front by turning that small ****. Now it stays up but appears to be
fully exposed. It does not go down with the drivers side light when lights are off.
I'd think as long as the inside light switch was in the off position it wouldn't drain
any current.

Would it be making any noises if it was trying to operate? I can't hear any noises.

Brad

 

Thanks Icemark