Hi,

so here's my recurring problem. I've just bought my 3rd battery in 2 months because of it.

Basically, I think that the anti theft device on my '86 GXL is draining my battery. When I put a fully charged battery in the car, everything works perfectly (although there is a buzzer that come on/off whenever I open/close the doors...don't know if that's normal ? )

However, even if I don't drive my car at all and let it sits in my driveway for a few days, my battery is still continuously running down...

My mechanic (who owns a rx8 and supposedly owned a rx7 like mine...) told me when I replaced the battery the first time, that I was locking the doors the wrong way, therefore activating the anti-theft device which was responsible for draining my battery. So, I tried locking them like he told me, without activating the anti-theft device (using the keys to lock the doors from the exterior of the car and NOT lifting the exterior handles at all), yet my 2nd battery was drained too.

I *think* that the last owner replaced the alternator with one from a FD. When I asked my mechanic to inspect my rx7, he told me that the alternator wasn't strong enough and that it would need to be replaced someday (however, I didn't have money for that at the time).

However, even if the problem only comes from the alternator, shouldn't my battery keep it's charge when I'm NOT driving it ?

Last question, if the problem comes from the anti-theft device, is there ANY way to remove it ? My mechanic told me that he wasn't able to do it and I guess that going to a mazda dealership will be expensive as hell...

thanks and sorry for the mixed-up post, I just didn't knew where to start hope it's readable..

 

If the previous owner installed an FD alternator, they may have wired it incorrectly. S4 alternators use a switched 12V source (R terminal) for the voltage regulator, while S5+ alternators use a constant 12V source (S terminal). If the B/W wire is left connected to a switched 12V source, then connected to an FD alternator's S terminal, it will drain your battery. To properly convert from a 70A S4 alternator to a 100A FD alternator, the power wire for the regulator must be re-routed to a fused, constant 12V source.

See the FAQ for a diagram: https://www.rx7club.com/showthread.p...72#post5131072

A simple test (besides checking the wiring) would be to charge the battery fully, then disconnect the alternator's B-post connection and the plug in the side. Come back after a day or so, and see if the battery still has a full charge, or if it is drained.

 

I have this same problem with my 86 GXL...The "Security system" light in my center console is always flashing no matter what. I believe I have all the stock alternator stuff and it charges the battery fine...could it be anything else while the car sits not in use?

 

Instead of having to wait a few days, could you use a multi-meter to see if you still have a parasitic draw with the 'B' Terminal disconnected?

 

Bro... if its buzzing (sorry but must refer to blondestar) Are you sure you are turning your key all the way before you take it out?

 

Thats proberly it man maybee ya have a dicky IGN or ya not turning the key far enough.

 

Ya alt might be draining ya battery to could be that or ya battery is stuffed.

How old is ya battery.

 

Pay attention to what Sgtblue is saying. Disconnect the Black cable to the alternator. Then disconnect the ground cable to the battery. Then take the multimeter and set to amps. Then take one meter lead and place it on the negative battery post and with the other meter terminal touch it to the disconnected batterycable and take the amperage reading which will indicate how much amperage draw/drain there is and tell us what you get. Usually the meter has two settings for amperage. One is for milliamps and the other generally is for reading amps up to 10 amps and this is the setting you want.

If you are compelled to believe the drain is alarm related you could then disconnect the wire powering the alarm after you take the amperage draw reading as explained above then take the reading once again w/the power wire to the alarm disconnected as stated and compare the two readings.