Alternator Swap

[captinsho]

I want to know if it is possible to use the alternator out of my 94 MTX (parts car) for my 93 ATX? I have a drain occuring so that when I park my car for any significant time (4 hours plus) the battery dies. I am sure the alternator itself is good because as soon as a get enough power to turn the motor over, when I jump it, it runs perfectly for as long as I like. Also if I disconnect the battery, like I have been doing every time I park it for the last two weeks, it starts right back up as soon as I reconnect and seems to have a good strong charge so I don't think it is the battery.

I think I have some sort of drain. I am thinking it could be my voltage regulator (had this problem on a Mustang I owned). Since the voltage regulator is located inside the alternator I was thinking I could swap my alternator out and see if the problem went away.

 

[Cobraii976]

they don't interchange. but I do have an ATX alt or 3

 

[captinsho]

they don't interchange. but I do have an ATX alt or 3

Thanks. I am going to try to get the ATX alternator tested and see if that is really my problem. I hate to just "throw parts" at a problem but electrical issues are not easy to figure out... at least not for me.

 

[wood_e]

ATXs have a 120 amp mechanism. 92-95 MTXs have a 130 amp mechanism.

 

[gmorrell]

Draining a fully charged auto battery in 4 hours represents dissipating a fair amount of power, something should be getting warm. The average car battery is rated 45 Amp-hours, so killing it in 4 hours means its seeing a 10 to 12 Amp drain, this should be easy to find.

I wouldn't rule out the alternator just yet, it could have a shorted diode in the rectifier pack; it will still charge, but with reduced output. Have you tried disconnecting the alternator charging wire and seeing if the battery still discharges? This is the large wire on the back of the alternator which is secured to a stud with a 10mm nut. Be careful here, this is a big-a** wire connected straight to battery positive, disconnect the battery cable first, then pull off the alternator output lead and insulate the wire lug with some tape.

If you suspect the internal voltage regulator, then pull the 3-pin connector from the side of the alternator, as this will disconnect battery positive from the regulator.