My Sup Eats Alternators For Lunch!

[Jose H. 3]

So first off, I already tried searching and didn't find exactly what I was looking for... so onto my prob. I bought one of those remanufactured alternators a while back and I know they are notorious for having a much shorter life span then the toyota ones do, but it came with a life time warranty so I figured what the hell. So the alternator shat out on me again this weekend, and that one only lasted 3 months :censored: !! And already it seems like the new one is on the way out... which was the same thing I went through three months ago, two alternators in one weekend. The alternator I'm on right now I think makes #5 for this year alone! I know they don't last as long but this is getting rediculous, I've heard they should last about a year or so, which would be fine. Does anyone have any idea why my car would be eating through so many alternators? Anything I should be looking for? It doesn't seem like anything is leaking onto the alternator, but I do have an aftermarket alarm and a small stereo set-up, but I'm not sure if those thigns would be killing my alternators that fast. I have a fairly stock 5M, with only an intake, and some exhaust work. If anyone has any ideas, shoot them my way! Thanks everyone...

Oh and by the way, each time this happens I have to get the alternator tested and they fail, and I just bought a new battery three months ago too when this happened last time...

[Dangerous Ken]

Through all of this, what is the condition of the battery?

Usually the voltage regulator goes on the alternator, and undue strain on the regulator is symptoms of a battery taking too hot a charge or never taking a full charge, thus always charging.

Ken

[Jose H. 3]

Well this weekend when it happened again, I took the battery to autozone cause it need to get charged and they tested it and they said it was fine, just needed a charge. Its only 3 months old (I just edited my first post). How can I find out if the battery is always taking charge? Oh and this morning when I was heading off to work, the volt gauge in the car was reading just below 12v, and stayed there the whole way to work, I didn't have the radio on or anything, just lights... it usually reads there right before the alternator poops out on me.

[BillyM]

Fix your power steering resevoir leak.?

--BillyM

[Jose H. 3]

I fixed a power steering leak over a year ago, I'll have to search and see if it has been acting up again. But when I jaked up my car this weekend, I started getting some collant, from I think is from the water pump, but it stopped leaking as soon as I put the car back down. I haven't had a leaking problem from the water pump before, until this weekend, but it wasn't getting the alternator wet, it just ran down the front of the block and pan. If this is the problem with the alternator now, it doesn't explain why it did this same thing three months ago.

[stevrock]

Well this weekend when it happened again, I took the battery to autozone cause it need to get charged and they tested it and they said it was fine, just needed a charge. Its only 3 months old (I just edited my first post). How can I find out if the battery is always taking charge? Oh and this morning when I was heading off to work, the volt gauge in the car was reading just below 12v, and stayed there the whole way to work, I didn't have the radio on or anything, just lights... it usually reads there right before the alternator poops out on me.

Correct me if I'm wrong, but if you have everything in the car turned off, then turn of the car and disconnect the battery and bring it in to be tested, shouldn't it have a full charge?

If that's the case your battery is at fault of your alternator problems.

[Kevin Kisseberth]

Do a load test while the car is running to test to see what the battery is being charged at. Remember they only fix what is wrong with a rebuilt alternator so maybe its just the alternator. You have to learn to do load test on the battery and on the alternator. While the car is running test what the battery is being charged at. It should be above ???12.7 I think and up to 14.4. I did three alternators on one car and finally the fourth one worked. Thats right four. So your on your way.

[Dangerous Ken]

Only other thing I can think of is the condition of your wiring.

Alarms are always suspect for battery drain.
I feel your pain; changed a starter, nothing.
Have to rip out the autostart et al alarm wiring now...

Ken

[Dangerous Ken]

Do a load test while the car is running to test to see what the battery is being charged at. Remember they only fix what is wrong with a rebuilt alternator so maybe its just the alternator. You have to learn to do load test on the battery and on the alternator. While the car is running test what the battery is being charged at. It should be above ???12.7 I think and up to 14.4. I did three alternators on one car and finally the fourth one worked. Thats right four. So your on your way.

Can you post the brands / places of alternators you went through? (Jose too)
I'm finding most <insert auto parts store here> alternators don't put out jack until 1500 rpm. Thus, I'm holding to Nippondenso is best.

Ken

[Jose H. 3]

I have always been a lil weird about the alarm and all that but I went through and replaced the one the last guy had in the car and checked it all out then. Now as for the condition of the wires under the hood I'm not all too sure about, it looks fine, but I haven't run any tests on them. I want to replace the battery terminals just to bee 100% sure I have a really good connection there too. I plan on stopping by the parts store again so they can hook up the car while its running to check everything that way.

Ken- All of the alternators I have gone through have been from Autozone, and the last few I have noticed were remanufactered by Duralast. And I can agree with you on the suspicion that they don't do crap before 1500rpm... as of right now with the one I just installed, the volt meter in the car sits a hair under 12v at idle and then around the 12.7 mark when I have it above 1500rpm... I'll have it tested soon... damn cheap alternators...

[KesekiSupra]

i was wondering, do the signal wiring to the alternator go bad over time? cuz i replaced my grounds, new battery, AND mkiii nippondeno alt mod. and it still sits a lil over 12 if not right at 12v sometimes with everything on (voltage at battery is 13.4 with everything on) and lights go dim idle, but get a bit brighter as i rev it up to almost 1k. im thinking that its not giving a signal to the alt to put out a lil more charge, either that or wiring to the alt isnt too great. ima figure it out one day that im not lazy, i swear it

[Jose H. 3]

I went and got the battery checked yesterday at autozone and it was reading a healthy 12.35V (car not running). Their attachment to check it with a load and to check the alternator while it is in the car was busted... so I didn't get to check that yet... Any other ideas why my sup would be burning through alternators? Oh, I have been keeping an eye out for any types of leaks above or around the alternator and so far all is dry. The last alternator that I pulled was dirty, but not wet from any kind of leaks...

[Uryoces]

Autozone, Duralast starter. It went bad 2 weeks after it was installed. Installing the starter in a Mark II is a two-man, PITA job. When Autozone tested it, blew the breaker on the test stand. He tried it again, blew it again. He started swearing under his breath and gave me a new one -- new, remanufactured Duralast. This one works so far.

[KesekiSupra]

eh without testing it with a load, its pretty much useless to test. the load IS the test

[omarty]

On the Yahoo MKII site This was discussed and several people responded. The solution was to get an altenator from a 1987 and above Supra. It puts out more amperage and plugs in fine. the difference is it is a single pully so you have to change that out and get the right belt.

[Gage006]

I changed mine a couple of weeks ago to a Duralast also and it's dying now. I also replaced the battery at the same time, so I know it's not one or the other causing it. It was REALLY good for the first week, voltage sitting above 12 all the time, ran great, lights were bright. Now, 2 weeks later, voltage sits at the line below 12 and lights barely look like they're on.

[Kevin Kisseberth]

Do A Load Test First

[Donn29]

Do a load test while the car is running to test to see what the battery is being charged at. Remember they only fix what is wrong with a rebuilt alternator so maybe its just the alternator. You have to learn to do load test on the battery and on the alternator. While the car is running test what the battery is being charged at. It should be above ???12.7 I think and up to 14.4. I did three alternators on one car and finally the fourth one worked. Thats right four. So your on your way.

13.8V is req'd, to charge a batt, any less will not work
yes do a load test, do a draw test
a draw test is: using a cheapo multimeter, that has a 3rd plug(says 10A) for the postive test lead. put the postive there and set the meter to 10A setting.
then disconnet the ground to the battery, and 'bridge the gap' with the mutlimeter

ground cable > test lead > mulitmeter > test lead > ground post on battery

make sure the key is off, nothing on. .1 amps will kill a battery/make it low all the time so it constanly is taking a charge, killing the alt.

ie: your alt dies, youve been driving around on the battery untill you realize the problem. and a brand new alt is installed. but the battery is dead.
so you take A HUGE chunk out the alt's life by completely chagring the battery.

while doing the draw test unplug the alarm. then pull fuses(one at a time) to see what is draining the battery

[dbdaniel]

Ol'supra guy told me about his alt swap, search for lexus alternator on the forum, anyway a lexus 80 amp alt from a 1992 es300 was what i just put in same holes, plug etc, only need to change the pulley from the original... now my supra runs like new.

[Rockheadjc]

good info

[racefanfoster]

Will the clock or memory in the radio produce a .1 amp draw??
13.8V is req'd, to charge a batt, any less will not work
yes do a load test, do a draw test
a draw test is: using a cheapo multimeter, that has a 3rd plug(says 10A) for the postive test lead. put the postive there and set the meter to 10A setting.
then disconnet the ground to the battery, and 'bridge the gap' with the mutlimeter

ground cable > test lead > mulitmeter > test lead > ground post on battery

make sure the key is off, nothing on. .1 amps will kill a battery/make it low all the time so it constanly is taking a charge, killing the alt.

ie: your alt dies, youve been driving around on the battery untill you realize the problem. and a brand new alt is installed. but the battery is dead.
so you take A HUGE chunk out the alt's life by completely chagring the battery.

while doing the draw test unplug the alarm. then pull fuses(one at a time) to see what is draining the battery

[Tire Shredder]

Only other thing I can think of is the condition of your wiring.

Alarms are always suspect for battery drain.
I feel your pain; changed a starter, nothing.
Have to rip out the autostart et al alarm wiring now...

Ken

this was the problem with my corolla. my main power supply wire was nearly infinite resistance. I cut open the starter supply cable and a couple of grounds....all were filled with black and green corrosion...solid! Prior to my wiring upgrade, it destroyed alternators at an astounding rate.

[dannyr]

i keep having em crap out on me as well. i got a cam tower gasket leak though :(

[ra24man]

this was the problem with my corolla. my main power supply wire was nearly infinite resistance. I cut open the starter supply cable and a couple of grounds....all were filled with black and green corrosion...solid! Prior to my wiring upgrade, it destroyed alternators at an astounding rate.
BINGO! That's usually the culprit Steve...green crud

Guys...check the resistance in all the wires that go to the alternator...you will probably find that a bad wire in your car is causing these alternator problems. Even a Denso reman wouldn't stand a chance against the Green Crud!

[Tire Shredder]

BINGO! That's usually the culprit Steve...green crud

Guys...check the resistance in all the wires that go to the alternator...you will probably find that a bad wire in your car is causing these alternator problems. Even a Denso reman wouldn't stand a chance against the Green Crud!

it's hands down the best, cheapest "Mod" i've ever done that helped the vehicle greatley. I replaced every wire on the supra aswell. I used 2 gauge welding wire from princess auto and used a propane torch with a closed-end terminals. I filled them up with solder and finished it off with some large shrink wrap. it does a nice, professional looking job.

the 2 gauge is overkill, but it can't be beat for the price!

jim king has a post somewhere on here outlining the benefits of running an additional alternator to battery wire...and the potential it has to prevent fuse box fires, let alone how it will make your alternator's life easier!

[Jose H. 3]

Wow... old thread. I am in the process of rebuilding my other MKII and decided on replacing/upgrading my main alternator cable... stock is an 8 gauge cable... I got 6 gauge for replacement... should I go with with a heavier cable? possibly a 4 or even 2 like tire shredder did? I haven't run the wire yet so its not too late. I haven't yet but may do an upgrade to the alternator in this MKII down the road a bit.