I have a 1985 Gsl-se. I was driving it tonight and i noticed that my battery gauge was moving when i would turn my left,right signal lights on. It really doesnt move much when i turn on everything though. the battery is less than a month old. It seems like it came out of no where. Is it a slowly dying alternator or do i just have a bad ground?

 

i had a problem like that, so i took to alternator out and batt. got it tested and checked out okay. Reconnected everything then it started to work perfectly fine. "just fyi napa or schucks have a tester they'll just hook up to your car and test everything for you on the spot, rather than taking everything out" they test batt. alter. and the starter at once. for free!!!

 

I highly recommend checking, cleaning or better yet replacing the battery connectors and cables. Clean solid ground points can do wonders for weird electrical problems. That said, what you are describing is not unusual. The turn signals seem to do it the most. The voltage meter should read above 12v most of the time. Its more complicated, but generally when it is below 12v battery power is being used. Above 12v battery is being charged.

Mine reads 13-14v at cruise with electric fan, 4) 100 watt halogen lights, red Optima, stock alternator with reduced diameter double pulley. Only the blower fan drops the reading to 12-13v. The turn signals flashing make the needle move further than anything else. I haven't replaced the 130k stock cables yet but I've replaced the terminal ends and cleaned the grounding points on the shock tower and the starter bolt.

 

+1. dont just blame the alternator; that is a very common mistake. If you still have a stock, you can add a second ground cable.

 

it's entirely common, specially at night when you have your lights on, and fan/radio on, if you're over paranoid, clean your grounds as suggested, and upgrade to a 2nd gen alternator if you want to.

 

ok yea so i think its probaly not the alternator. i will get it tested today if i can. i was driving it to work and i noticed putting the car in reverse it moves. as soon and i put the shifter in reverse the gauge goes down for that as well.im thinking something is crossed up badly or something not grounded anymore

 

alright so a follow up. i ended up getting the battery,alternator tested and the alternator came out with low charging volts. and it was starting to kill my battery. So i go to order a new one from advance auto and it comes in a day later. I go to put the thing on and it no where NEAR fits. the brackets are to close together where it bolts by the waterpump to fit that spacer in. So i go back and we pull up all the alternators for 12a,13b and they all looked like the way i had bought. but the one i took off of the se was alot bigger with fins right behind the pulley. The only thing they found that looked like it was from a 1985 Mazda GLC. I havent really even heard of that car before and they had 1.5 liters in them. How is this possible that alternator ended up on my Car?

 

At some point Mazda changed from the external fan that you have to an internal fan. I believe 84-85 is when this happened. Sounds like you had an earlier model. Is the spacer just a little too big? If so, there is a bushing in the rear arm of the alternator that can be driven in or out to allow the spacer to fit. SE alternator looks like this.

 

yea the spacer was to big. i ended up going with the old one because it bolted up easier. i wonder how many volts it is?

 

hey 74rx4 did you take out some of the wiring at the intake, i noticed a missing piece near the bac.

 

Clean up your grounds anyway. That could be the reason for the alternator's death...

 

Yep. The plastic insulator on the plenum broke like they often do. The wire is connected directly to the alternator instead of the broken terminal. The short jumper wire from the terminal to the alternator is removed.

 

BTW here's a good link about swapping alternators between different models.

http://www.rx7.org/public/altxref.html

 

oh, i must be lucky then.

soon will put in s5 alternator, cause it looks cool and i think mine will go out soon