GST kills alternators

[4g63-pwr]

Ok, I have a 99 GST for a daily driver and it has an annoying habit of killing alternators. I've had the car for just over 2.5 years and I am about to put the 7th new alternator in it. The actual act of replacing it doesn't bother me since I'm now such a seasoned veteran at it and it only take me about 15-20 minutes to swap out.

The car now has 135k miles. I originally replaced the OEM one at around 90k miles with one from an autoparts store that had a lifetime warranty. After it crapped out about 3 times I got tired of dealing with remanufactured alternators so I went to the dealership and pick up a brand new, OEM unit for $400 that came with a 6 month warranty. It crapped out 7 months later so I had to swallow the $400 I spent on it. Mad about that, I went back to the cheaper alternators with a lifetime warranty. I replaced the thing 18 days ago and it just crapped out again today.

For the life of me I can not figure out why they keep dying. I have a brand new battery, no shorts or drain, no big stereo system, just a few bolt-on mods and the car is in perfect running condition.

This is just fairly annoying being that this is my daily driver and this will be the 7th alternator in such a little amount of time. I also have a 99 GSX which I've had forever and it's still on the original one and never has had any problems with this type of thing.

Any ideas as to what may be causing this or how I can avoid replacing my alternator once a month (aside from selling it) would be greatly appreciated

 

[romeen]

Filling out your modifications (even if it's just a few bolt-on mods) in your profile will make it easier to help you.

Heat is what typically kills an alternator. Have you removed any of the heat shields?

Do you have a dump tube?

Any exhaust leaks, particularly at O2 housing-DP?

 

[DGajre777]

I agree with the post above. Heat kills alternators. Are all your heat shields on? Any exhaust leaks in the engine bay?

Mitsubishi doesn't make new alternators, all their alternators are rebuilt. What part of the alternator keeps dying in your car? Is it the voltage regulator? You could try a Bosch alternator, they have 100% new parts and it will run you about $450 (last time I checked).

 

[4g63-pwr]

The only mods I have on it is a 3" turboback exhaust, Injen intake, manual boost controller, supra sidemount, Mishimoto radiator, Odyssey battery, ngk plugs and wires.

I have the stock manifold, turbo and o2 housing on there and there are no exhaust leaks. It also still has all of the factory heatshields on it as well and no dump tube.

The voltage regulator was the culprit on the original OEM unit. The other 6 times it was just the alternator producing low voltage

 

[gixxerdrew]

I stopped using parts store alternators because no one of them lasted more than 8 months. Heat and oil exposure are common causes but I just dont think the parts store cheapo ones are reliable in any case. Maybe some stores or some units are good but my experience I never found a good one.

 

[JayRolla]

Well the bad regulator can happen from bad wiring, I had that issue. How tight do you tighten your belts. An overtightened belt can kill any accessory running on them.

 

[4g63-pwr]

^ I don't think I'm over tightening them. They are just snug. I never just tighten them as tight as they will go. The wiring is also fine. I've double checked all of the wiring for the battery, grounds and alternator as well as doing running test to check for shorts and drains

I stopped using parts store alternators because no one of them lasted more than 8 months. Heat and oil exposure are common causes but I just dont think the parts store cheapo ones are reliable in any case. Maybe some stores or some units are good but my experience I never found a good one.

I've tried using other ones but they don't last any longer either. I've tried one from Mitsu, several from autoparts stores and 2 other OEM units from other cars. They all die.

I don't have any oil leaks either. The alternator is always spotless.

 

[Jeff99GS]

Take a voltage meter and check the output voltage on the alternator and at the battery while the car is running.

It should be 14.4ish while running

Then Check the battery volts while the car is off 11v-12v is normal

Do you have OEM pulleys, or Aftermarket?

 

[gpz750]

I'm having the same problem, just more often. My car killed 2 good oem alternators in 100 miles. Found out the red top had an internal short. So I thought we had it fixed. Next one lasted 50 miles. SO we checked the wiring again. The grounds are good, and the positive showsno sighns of being bad. We put another orielly's unit on, and it's on the way out with 50 miles on it. Only thing we found was that at the alternator it was showing 13.3 idleing and 13.0 at the fuse. It never put out more than that from the get go. It did come with a smaller pulley than stock, so I swapped them to use the stock one. Does anybody think that is an issue? I have all the heat shields on. Is the fmic causing it to run hotter in the hood compartment?

 

[ekanddsm]

Check the power cable from the alternator to the battery, How much resistance does it have? Your alternator might be working too hard to charge through a bad cable.

Or you may have a ecm going south in the charging circuit.

 

[4g63-pwr]

Take a voltage meter and check the output voltage on the alternator and at the battery while the car is running.

It should be 14.4ish while running

Then Check the battery volts while the car is off 11v-12v is normal

Do you have OEM pulleys, or Aftermarket?

I already have. The battery is brand new and puts out 12v when off. The alternator is brand new and puts out 11v at idle.

I have stock pulleys

Check the power cable from the alternator to the battery, How much resistance does it have? Your alternator might be working too hard to charge through a bad cable.

Or you may have a ecm going south in the charging circuit.

The power cable the alternator, battery and fuse is good. I've checked it and even rewired some with better cable and connectors before thinking it was the problem. It is better than the stock wiring.

 

[gpz750]

What exactly is the ecm function in the charging system?

 

[Jeff99GS]

The alternator is brand new and puts out 11v at idle.
.

It puts out 11v AT IDLE?!?! Was that a typo? Or does it really put out 11v at idle?


Make sure you have a good Chassie ground. Run a ground strap from the negative battery terminal to a point on the car.

 

[4g63-pwr]

It actually puts out around 11.5v at idle right now. The alternator is not charging at all. It's only good for a paperweight. If you read back I've already stated that my grounds are fine. I've checked all wiring

The point is that the alternator is 18 days old and already completely useless............for the 7th time in 2.5 years

 

[gpz750]

Can someone elaborate on the possibility of the belt being too tight causing problems?
I'm very interested to know what the ecm function is in the charging system too. The way it looked to me was that it progessively turned the voltage up when something was turned on like the lights.
4g63 does your battery light come on? Mine didn't come on until the battery was dead. Put a charge on it and started the car and the alternator was not putting out, but the light still did not come on.

 

[4g63-pwr]

Yes, my battery light pops on every time my alternator dies.

 

[1gDSM4g63]

Making sure the power steering fluid isn't dripping on the alternator. I been in the situation too with two DSMs and I took both power steering pumps out and that solved the problem.

As for the heat, I'm pretty sure that doesn't have any effects on the alternator. One of my cars is built and has a big turbo with no heat shield or anything that dissipates heat and it has limited driving time for the heat situation but I don't have a problem with the alternator.

 

[4g63-pwr]

Making sure the power steering fluid isn't dripping on the alternator. I been in the situation too with two DSMs and I took both power steering pumps out and that solved the problem.

As for the heat, I'm pretty sure that doesn't have any effects on the alternator. One of my cars is built and has a big turbo with no heat shield or anything that dissipates heat and it has limited driving time for the heat situation but I don't have a problem with the alternator.

I don't have any oil leaks either. The alternator is always spotless.

No leaks of any kind

I also have had my 99 GSX for 9 years and have never had one alternator problem. It still has the stock OEM alternator despite being extensively modified and running dozens of track events. That's what is irritating me. I have one that is a track slut and have never had any problems while my daily driver gets driven like a grandma and I can't even keep an alternator on it. It's very annoying. Both cars are maintained very well.

 

[Jeff99GS]

Can someone elaborate on the possibility of the belt being too tight causing problems?
I'm very interested to know what the ecm function is in the charging system too. The way it looked to me was that it progessively turned the voltage up when something was turned on like the lights.
4g63 does your battery light come on? Mine didn't come on until the battery was dead. Put a charge on it and started the car and the alternator was not putting out, but the light still did not come on.

The belt being too tight usually causes the bearings in the alt to prematurely fail. It has to be pretty damn tight for that to happen though.

 

[4g63-pwr]

Well I did some work to combat this problem. I heat wrapped the downpipe and 02 sensor housing, fabbed a better heatshield, installed new exhaust manifold gasket, turbo gasket, o2 housing gasket and downpipe gasket and torqued everything to spec. The car still has zero oil, coolant or power steering leaks.

But yet, it is still time to install alternator number 8 on the GST.

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On the bright side, atleast it only takes me 10-15 minutes to swap them out now.

 

[Detail]

cute. I'm at over 17 in 2.5 years. They suck. That said, check for exhuast leaks, power steering leaks, and coolant leaks that may be spraying and then evaporating.

 

[luv2rallye]

A leaking power steering unit that drips onto the alt below it will kill every alt you put in.

 

[DGajre777]

Get a vented hood.

 

[cgmtboarder]

ive had the same problem as well. im on my 6th one in about 3 years. few of them were from oil leak on it. now i dont know. want to know more about ECU as well. im having other problems with the car and wondering if all of it is coming from a leaky capicitor in ecu. one looks like it may be leaking.