bigbangjosh

I just bought an 89 240sx hatch last week at a great price. It is absolutely mint with no rust and a tiny dent. Anyways, I test drove it and it was great. I was driving it home when I noticed the car would die for half a second and pop right back on. Finally the car died for good on the highway. It did one of those flickers with the car dieing, and then the A/T trans went out then the car died for good about 1 second later. Basically when I stepped on the gas the revs went up without moving the car. I popped the hood to notice that the negative terminal was off and barley touching the battery, I mean barely. The positive terminal was on, but popped right off by hand. I charged the battery and put the terminals on correctly, ie tight, and the car started right up. Unfortunately the trans did not work. It goes into gear, ie N works and reverse pops on the lights, but it just free revs when I step on the gas. I checked the fluid level in the A/T and it seemed fine. Anyways, I hooked up my voltmeter and noticed that the alternator wasnt charging the battery fully and the more accessories I turned on the worse it got. Anyways, a friend of mine who owns a tuner shop thought that the alternator could cause the trans to do that. I definately see where he is coming from since I had a similar problem with a AEM alternator pulley on my 02 WRX. Anyways, I just bought an alternator and was wondering if anybody knows if it would fix it or what other things I can do to fix it. The trans shifted absolutely perfect when the car was running. It was strong with not once ever slipping or anything like that. PLEASE HELP!

bigbangjosh

Basically the WRX alternator problem was when I put on an aftermarket pulley and it didnt have enough power to open and close the circuit for the headlights. They always stayed on even with the car off or the headlights off. Taking off the pulley fixed the problem. I think that the old crappy alternator, which is covered in about 1/4 of muck since the car has 200K miles on it, doesnt have the power to turn back on the A/T control unit. Does this sound about right?

LA_phantom_240

Um no? it sounds to me like you got boned on a sale. The tranny is mechanical, for the most part, and shift points IIRC are electronically controlled by the ECU, which also controls engine functions. Therefore, as far as i see it, If the motor is running, the ECU is fine, which means it should be able to shift normally, provided the tranny is still good.

Bryan

I'm moving this to drivetrain, sorry I don't really have an answer, don't have too much experience with auto's, I'm sure someone here will help you out

bigbangjosh

Thanks for the help. I just find it so incredible odd that the trans and alternator/battery went out similtaniously. Ohh well, I will let you guys know if by some odd fluke it does work. If not I have a car for sale soon. THanks again.