1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Dead Alternator?

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Old May 13, 2007 | 03:39 PM
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Dead Alternator?

Just wanted to double check as I am new to rx7's...but battery is dead

so i jumped it, got it started...pulled the negative terminal on the battery and the car dies. I've always known that as a good test of battery dead vs. bad alternator. just wanted to make sure the same was true for rx7's

BTW, 83 RX7 with 12a
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Old May 13, 2007 | 03:55 PM
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Also, another stupid question...Are those little plastic lines that route underneath the alternator, really the omp lines? no wonder they leak
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Old May 13, 2007 | 04:15 PM
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Yes and yes.
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Old May 13, 2007 | 05:31 PM
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Took the alternator over to autozone and it tested fine. I guess I'll have the battery tested as well. Any other ideas?

Thanks
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Old May 13, 2007 | 07:35 PM
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Check the rest of the charging system and ignition wiring.
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Old May 14, 2007 | 11:45 AM
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Battery tested fine as well. Wiring looks fine. I'm thinking bad starter. It's a reman autozone one, so i'm not too confident in it
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Old May 14, 2007 | 12:17 PM
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So the only problem is starting? Everything else works well, headlights etc?

And test the wiring. Wiring can "look" fine and be corroded to hell.
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Old May 14, 2007 | 12:33 PM
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Well from what I understand, the ground strap from the battery is a problem on these RX7's...I already pulled the starter, but I called autozone and they said they can only test starters if they can disable it from trying to start. They said odds were that no one that worked there knew how to do it on a mazda starter. i'll take a look at the wiring again, but would also like to know if anyone has any idea on how to test the starter.

Also, the car turn signals weren't working right the night before it wouldn't start. The starter has always been finicky (as in it seems to have flat spots)...I generally have to try it a couple times before it catches and starts.

Any help would be much appreciated.

My main automotive experience is with honda's so a lot of this mazda stuff is new to me. thanks

EDIT: Also, on the last night, headlights did appear to be dull, however it could have just been my imagination

Last edited by cberman; May 14, 2007 at 12:58 PM.
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Old May 14, 2007 | 06:20 PM
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Starter is fine. I guess now im gonna go in there with some sandpaper and clean the grounds. Any other connections in particular I should pay extra attention to?
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Old May 14, 2007 | 07:10 PM
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Quite often the + cable corrodes internally, hidden by the sheathing, it's aluminum wire. It's better to simply replace them if they're still the original ones.
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Old May 14, 2007 | 07:40 PM
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The ground wire attaches to the strut tower. Just replace that whole chunk of wire. You can get prefab cables with the battery clamp already attached from PartSource or other aftermarket supply stores.
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Old May 14, 2007 | 09:56 PM
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Originally Posted by Manntis
The ground wire attaches to the strut tower. Just replace that whole chunk of wire. You can get prefab cables with the battery clamp already attached from PartSource or other aftermarket supply stores.
Is it just the ground wire that is aluminum, or should I go about replacing more of them
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Old May 14, 2007 | 10:24 PM
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Ground is copper, positive cable is aluminum. If they are original, replace both of them.
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Old May 14, 2007 | 10:50 PM
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...which is a good excuse to relocate the battery to the rear right cargo bin, if you're so inclined
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Old May 16, 2007 | 08:46 PM
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It was the wiring apparently..Replaced it all with copper and sanded down the chasis and engine ground points.

thanks all
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Old May 17, 2007 | 05:35 PM
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Strike that last statement. Apparently the car was okay just because the battery was fully charged. The battery drained today. Any other ideas?
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Old May 17, 2007 | 05:44 PM
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sure the alternator is fine??? or maby your belt is loose??? really sounds like an alternator problem.... dunno tho hard to say
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Old May 17, 2007 | 05:52 PM
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Well, at this point I think my next step is to run a wire directly from the battery to the alternator. Any problems with that, assuming its just temporary
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Old May 17, 2007 | 06:20 PM
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The 1.25sq fuseble link completes the circuit to your alternator and kick down solenoid. are you sure that link is okay and not blown?
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Old May 17, 2007 | 06:21 PM
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For future checks you cn tell if the alternator is making power by touching the center bearing cover on the back with a screwdriver to see if its magnetic. (with the car running of course). Magnetic=working
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Old May 17, 2007 | 07:21 PM
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Originally Posted by Manntis
The 1.25sq fuseble link completes the circuit to your alternator and kick down solenoid. are you sure that link is okay and not blown?
How would i test it? Just a multimeter to make sure current is passing through?
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Old May 17, 2007 | 08:33 PM
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Originally Posted by cberman
How would i test it? Just a multimeter to make sure current is passing through?
NVM...I just read the archived article about replacing fusible links with new style ones(box style fuses)...Im just gonna go ahead and get a couple of em just incase. If they aren't blown already, its just a little extra reliability in the future
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Old May 17, 2007 | 09:20 PM
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remember to get the long shank version, so you don't have to trim any plastic to make 'em fit.
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Old May 19, 2007 | 12:27 PM
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I'm getting real frustrated now. Put a new battery in a couple days ago and it ran fine all yesturday and part of the day before. Yesturday I replaced the fusible links. This morning, my car won't even crank. However, when I turn the key, the voltmeter reads right around 12v.
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Old May 19, 2007 | 12:36 PM
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does it click? Any chance the solenoid wire came off the starter?
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