i am having tons of problems with my alternator. i have put two in in the past week and my voltage is still dropping when i turn on headlights, a/c, etc. i had a dual belt pulley on my old alternator but i took it off in hopes that with only turning one belt the alternator would not drop voltage but it didn't. so i got two problems, one is i still can't figure out why my voltage drops, and also since i only have one belt running the alternator and only one belt touching the water pump, does this create a problem? heard somewhere that this would cause me problems. any ideas would be awsome.

 

Taking off the double pulley gained you nothing- obviously- mainly because the alternator isn't driving the belts, it's being driven.
The dual belt setup is specifically aimed at making sure the waterpump gets driven, it can slip if only one belt is being used.

 

Where did you get your replacement alternators? A lot of reman & used ones are junk from the start. Go with OEM Mazda or a higher end parts store like Napa.

 

I have almost the same prob with yours, but mine was due to "underdrive" main crank pulley. If you got a stock main crank pulley and your car is an s4, then using an FD alt (with the appropriate pulley) will solve your voltage issue.

 

Not Exactly G(Karmadi)!..I got an FD alt on my s4 with the appropriate pulley.For some reason it is doing the same darn thing that the last S4 alternator was doing.Lits dim until after Idle.Once I touch the gas,the Volts go up,but at idle,I am at 11 Point something..during Drving the Alternator is above 12,close to 13V's.I'm gonna have the Regulator Checked.

 

the thing about the belt slipping with only one belt, does this happen even on a completely stock motor? because i do consistantly have my car above 5000 rpm on a daily basis. i definitely don't baby it.

 

Dave, are you still using the stock clutch fan? or are you using the efan??
If you are still on the stock clutch fan, then this can't be. Unless you got some crazy amp (sound system) in your car.
better check your alt...(or are you using racing main crank pulley as well??)

 

I am in the middle of pmed conversation with "680RWHP12A". He is a vendor in this forum and he is selling an HO fd alt (170amp). I am going to purchase this and hope this will solve my issue. This also may work for both of you...

 

Oh..I saw that Alternator..Very Nice "little" upgrade.If I do Say so.(I said it.heh!)..I have a guy hrer locally though,That is all he does,is Alternators and Starters.So I have to See WTF is up with it..after all,I Got it NEW..from..Well George..you know WHO,But no names..I'm not that "vengeful".Cheers,STYX.

 

Do you have any non stock electrical loads? If so, the problem may be that the alternator does not have adequate capacity.

If you have only stock loads and you have this problem, you could have a faulty battery. This could cause the very behavior you are describing.

If you have extra electrical load, here is a suggestion:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/130-amp-alternator-sweetness-785082/

Good luck!

 

you might look into the main power wire going to the alt. when i played my stereo my lights would dim and voltage dropped and had trouble starting due to dead battery for a couple of years so finally i took it to an alt. electrical system shop and they stripped some wire housing away from the wire and saw it was corroted*curroted* not sure how its spelled either way you could not even tell until he stripped it back so i had Karack replace the wire with a new one and have never had the problem since... worth a shot to check it out.....

 

Good point. Clean connections are a required for your electrical system to work properly.