chuckwizowski

Howdy all!

Recently my rex has decided to have a few electrical problems
First my tach decided to place itself around 5000 rpms at idle... weird? I think so.
I figured, hey, check the fuse, no biggie. I grab a bunch of 10, 15, and 20 amp fuses from the garage and head out to check it out. Good thing I grabbed the fuses because a few are incorrectly placed according to the owners manual

Nothing.

The tach still "begins" at 5000 rpms, basically acting regularly but "starts" at 5000, as if 5000 was 0. Also the three middle warning lights are on, the add coolant, gen, and ...one other... Id run out to the car but its raining and the light escapes me as of now. The car felt sputtery after more than about half throttle too and would almost fall on its face if i tried to give it more than half. I turned around immediately and limped home a few miles. The car died, but luckily inside my neighborhood. It wouldn't start, wouldn't turn over, nothing. I walked back to the house after pushing the car into a suitable "parking place." I came back in the morning with a jump box to see what would happen. I tried starting the car without the box and hey! it started! So i drove the half mile or so home

Ok long story short this is what i think happened and I'd like someone elses opinion and / or confirmation . I think the alternator is dying / dead, thus why the car sputtered and eventually died while driving (running on battery power alone?). This could also explain the fritzy electronics??

Any help?

Thank you infinite wisdom of RX7Club!!!

Siraniko

iTrader: (13)

dead

bliffle

Sounds like alternator. Erratic tach and peculiar idiot lights are typical symptoms.

Bad alt diodes could interrupt battery voltage to coils, thus causing erratic behaviour.

You could check the alt with a voltmeter, and check battery voltage for peculiarities, but probably it's the diodes in the alt burning out. Pretty cheap and easy to replace.

rrob311

I have the exact same problem with my 79 rx7. Mine has an external voltage regulator. I took the top off of it and there was an open wire. I am poor so I couldnt afford a new OEM regulator so I bought a couple off ebay. The first one wasnt the right one I dont think. So I bought a new Alternator. Same problem. I just recently bought a standard voltage regulator that the parts catalog called for but I have the same problem. I think the OEM regulator would cure my problem but I don't know how to full field the alternator to test it. + I don't think anyone at the parts house will know how to test it unless I find an old timer who remembers externally regulated alternators. But I think the most economical way would be to take your alternator to a qualified parts store to test it on a machine.

DivinDriver

iTrader: (15)

Voltage regulation, or possibly bad grounding.