Cheap HO Alternator Failure

[TheTubeAmper]

Hello,

Just wanted to share my story of my cheap ebay HO Alternator failing tonight, just to show how extreme the failure may be.

I purchased a $140, 140Amp HO Alternator on eBay back in mid August for my 1996 Mazda Protege. The car (being a small four door japanese sedan with a 1.5L engine) had a stock alternator with just 65Amps. I installed the alternator in mid August and it has been used HARD since.

I run 2x Sundown Audio SA-10's on a Rockford Fosgate P1000.1 and some RF Punch mids and highs off of a 400.4 I have an XS Power D5100R (installed a month ago) under the hood, and that's it for batteries. I never got around to doing 2 parts of the big three, the upgraded engine ground, and the upgraded alternator power wire.

As I said, I work the alternator very hard, basically taking my amps to clipping for an hour to sometimes two hours a day or every other day (as this is my daily driver).

All was well for those four months up until tonight, when I went for a one hour drive, all the while, blasting my music. I was about a mile from my house when my headlights flickered and my head unit spontaneously shut off. I quickly noticed that my voltage at the battery (usually about 14.1 no load, maybe 13.6 under load) was up at about 15.1 volts and rising.

I new then and there my alternator (or at least its regulator) had had enough. I cranked the heater full blast, turned on the defroster, I had all my lights on including my cabin light but still it wasn't enough. My voltage was at about 15.8 and still rising so I resorted to holding all four of my window buttons in the up position (they were already up) and this put enough of a load on the alternator to bring it down to about 14.6.

Now all this was happening as I was going 55Mph on a 2 lane highway with no shoulders at night. I turned down a road after about a minute of my voltage still staying at 14.6 even under load.

I then shut the car off, and this was apparently not a good idea at all. I immediately tried to start it back up and was horrified to find the entire car was dead, nothing would work at all.

I got out and checked my factory fuse box, the 80A "Main" fuse (or it may be one of those automatically resetting circuit breakers, either way, it was certainly blown up to the point where It'd not work again) was slightly melted and also quite warm. I thought perhaps I could swap this fuse for an adjacent 50amp that went to something I didn't need, just so I could get it home, but was again horrified, to find that this blown 80A fuse had welded itself into its holder, so at least for not, it wasn't coming out.

I decided I'd bypass the fuse (I saw the bolts and terminals underneath this particular fuse on each side, so I could put a big alligator clamp (which I had with me from an inverter) across these to effectively bypass the fuse. Only problem was that the alternator would then have free reign to fry anything else it felt like it wanted, so I decided I'd have to disconnect it.

So at night on a little service road, in 10F weather, I ripped out my cruse control actuator, and eventually got the B+ wire off of the alternator.

I then decided the alligator clamp may not work well, as it would've stuck out of the fuse box quite a bit, and been dangerously close to hitting my hood. So I then opted to grabbing a pair of channel locks and completely destroying the plastic casing of this 80A fuse and squishing the contacts of it together and twisting it slightly so It'd hopefully stay attached long enough for me to get home (about 5 minutes away).

I put the key in and was relieved to see the car start up and see the battery sitting at 12.2 volts, easily enough for me to drive a mile home. So I got it home, parked it and that's it. I'll throw my stock alternator back in it later this week and attempt to remove that welded fuse (though I may have to resort to getting a junkyard fuse box).

As of now I have no idea if this disaster ruined either of my amps, or my head unit. I must be grateful though that it didn't ruin my battery or especially my ECU (both of which I had feared would've cooked).

This just goes to show what can happen if you buy a cheap HO alternator, and romp on it as hard as you would with a quality HO alternator. I realize that some of us (like me) who have cars that don't have any quality HO alternators available (simply because who wants to load up a tiny 1.5L engine with a 140amp alternator, not many) have to use what we can find (the cheap HO alts) but I just wanted to show how bad this can turn out. For the most part I expect alternators to just have no output when they die, and in which case I'd expect to drive home on my battery. This failure however, totally blew that theory to bits, as this failure ended up totally immobilizing my car, as well as almost ruining my battery and ECU, and possibly frying my amps and head unit.

[ShadeTreeMechanic]

Good to know. I have a 250A ebay special on my bronco. Now I am thinking....

I would suspect your head unit and amps shut down or went into protect on the higher voltage. One time I tried to use a 24vdc power supply to run some amps on the workbench. My Toshiba 4 channel (75X4) would just shut down. Tried again on 12v AOK. My radioshack amp (25X2) took it like a champ and I ran it for a few minuets on a pair of 10s until I chickened out.

[MotorCityFats13]

alts have quite a few ways that they can fail.... and regulators can fail in either direction... this could happen to any alt but I would agree that the ebay alts could fail more often.... and there is no way to believe what this alt was really puting out or what the seller did to it to make it put out more juice and at what rpm it would start making usable amps... some people simply mod the regulator.... I doubt it had all new windings because a 70amp stocker rebuild with a limited lifetime is only $130..... holding up your window switch could have played a large factor in the melted fuse..... +/- 1 volt dc shouldnt cause any problems so I cant see 1.5 for a short period of time blowing anything up

[TheTubeAmper]

Good to know. I have a 250A ebay special on my bronco. Now I am thinking....

I would suspect your head unit and amps shut down or went into protect on the higher voltage. One time I tried to use a 24vdc power supply to run some amps on the workbench. My Toshiba 4 channel (75X4) would just shut down. Tried again on 12v AOK. My radioshack amp (25X2) took it like a champ and I ran it for a few minuets on a pair of 10s until I chickened out.

Yeah I would hope my gear shut itself down to protect itself. I do know that at some point while the voltage was in the high 14's my headunit back on. It would've reset itself when the fuse went, so on the ride home at 12V it wouldn't have turned itself back on as it doesn't remember being turned on before. We'll find out tomorrow if my gear survived.

alts have quite a few ways that they can fail.... and regulators can fail in either direction... this could happen to any alt but I would agree that the ebay alts could fail more often.... and there is no way to believe what this alt was really puting out or what the seller did to it to make it put out more juice and at what rpm it would start making usable amps... some people simply mod the regulator.... I doubt it had all new windings because a 70amp stocker rebuild with a limited lifetime is only $130..... holding up your window switch could have played a large factor in the melted fuse..... +/- 1 volt dc shouldnt cause any problems so I cant see 1.5 for a short period of time blowing anything up

Yeah it's a shame that I don't yet have a clamp meter, I've been wanting one for a while now. But I honestly do think it was putting out darn close to the 140 it claims to (even though I believe it only does so at a higher rpm than the 2K it promises) as it seems to keep up with about 1200WRMS of amplifiers.

The fuse was honestly really confusing to me. I'm no newbie to electronics, but I'm not the best with automotive electronics. I'm not sure what this "main fuse" is actually in between. I'm guessing the alternator is basically hard wired to the battery (talking stock as I said I never did this part of the big three upgrade) and that the stock power going to that main fuse box (and thus the whole car) goes through that 80A main fuse from the battery/alternator, instead of having a separate fuse for battery and alternator, or (at least from what I saw) a fuse between the alternator and battery. But the actual confusing part is why this fuse decided to crap out after I parked my car, as I shut the car off.

I'm not sure how I feel about that voltage. I see most input caps on automotive electronics are 16V caps so I guess I technically should be safe as far as they go, but its still pushing it none the less. I'm amazed my ECU didn't just die on the spot when the voltage originally went up to about 16, I really didn't believe they were that tolerant.

Here's one thing where my knowledge really doesn't extend to. Do you think my battery is still going to be as healthy as any other 1 month old battery that wasn't hit with 16V for like two minutes?

[MotorCityFats13]

ive never seen a fuse between the alt and battery.... there is an 8awg wire from the charging post directly to the battery.... if you had this wire fused you would need a fuse at both ends because many alts do not automatically shut off when shorted out..... and I would think your battery is fine getting 1.5vdc extra for less than 5 minutes..... and just because your gage was staying low when you were loading it up does not meen that it was not still at 15.8vdc+.... when you are hitting heavy bass your amp might see a drop but the alt is still putting out 14.4vdc to check this you would have to put a dmm directly on the charging post of the alt

[TheTubeAmper]

ive never seen a fuse between the alt and battery.... there is an 8awg wire from the charging post directly to the battery.... if you had this wire fused you would need a fuse at both ends because many alts do not automatically shut off when shorted out..... and I would think your battery is fine getting 1.5vdc extra for less than 5 minutes..... and just because your gage was staying low when you were loading it up does not meen that it was not still at 15.8vdc+.... when you are hitting heavy bass your amp might see a drop but the alt is still putting out 14.4vdc to check this you would have to put a dmm directly on the charging post of the alt

Well when I was saying that I was loading up the car and that the voltage was dropping, I do realize that I may have just been experiencing the drop over that single 8GA wire between the alt and bat, I could care less what my alternator was really outputing at that point, I was just worried about saving my car from the rising voltage. TBH the voltmeter I put in my dash just reads the voltage on my accessory power from the key, but I do know that's usually about .1v lower than what the actual battery voltage is (I checked this with my nice Fluke). I do plan on doing a bit of tieing up loose ends and hopefully getting a few meters to measure directly some different spots like front battery and back battery when I do put in another battery)

I'm currently not real concerned with whatever my voltage drop is across that 8GA wire, It hasn't been much of an issue even since I got the HO alt.

I did recently order some more shit for my car, and I did get some more 4GA to finish up my big three upgrade, so once I actually get another HO alt in the car, I'll finish the big 3, but for the moment, I just need to find some spare time this week to throw my stock alt back in. Hopefully said stock alternator is OK as it's been sitting outside for the last three months, maybe half covered from the rain. Then I need to figure out how to deal with whats left of that welded in fuse.

Also I guess your right, I'm probably being a bit paranoid about the battery, it wasn't warm or anything that I noticed while messing with the car on the side of the road.

At least my ebay alt came with a one year warranty where I'm supposed to be able to send it back and get another basically without question, we'll see how that goes.

[Bayuk89]

hope everything works out for ya man, sorry u had a bad experience.

[MrSkippyJ]

ive never seen a fuse between the alt and battery.... there is an 8awg wire from the charging post directly to the battery.... if you had this wire fused you would need a fuse at both ends because many alts do not automatically shut off when shorted out..... and I would think your battery is fine getting 1.5vdc extra for less than 5 minutes..... and just because your gage was staying low when you were loading it up does not meen that it was not still at 15.8vdc+.... when you are hitting heavy bass your amp might see a drop but the alt is still putting out 14.4vdc to check this you would have to put a dmm directly on the charging post of the alt

Both my Scion and my f150 have a factory fuse between the alt and battery.

[TheTubeAmper]

hope everything works out for ya man, sorry u had a bad experience.

So far everything seems fine, except for that fuse which is stuck in my fuse box. I might have to get creative on removing that fuse. It looks like If I'm unable to remove said fuse that I may be able to unbolt the wires going to and from said fuse and use a normal ANL fuse and fuse holder instead.

ive never seen a fuse between the alt and battery.... there is an 8awg wire from the charging post directly to the battery.... if you had this wire fused you would need a fuse at both ends because many alts do not automatically shut off when shorted out..... and I would think your battery is fine getting 1.5vdc extra for less than 5 minutes..... and just because your gage was staying low when you were loading it up does not meen that it was not still at 15.8vdc+.... when you are hitting heavy bass your amp might see a drop but the alt is still putting out 14.4vdc to check this you would have to put a dmm directly on the charging post of the alt

Both my Scion and my f150 have a factory fuse between the alt and battery.

Yeah I would've thought It'd be wise for manufacturers to have a fuse between the alt and battery, but I suppose MotorCityFats13 is correct in that most of the time there isn't (including my car, although I will be putting in a 200A fuse between my 140A alt and bat when I do the rest of my big three).

Well thankfully my employer has allowed me to fix my car in our building tonight, so I won't have to be out in the cold PA weather. I'll keep you all updated (with some pics) about how it goes, especially with the fuse dilemma.

[jcarter1885]

Dont put a 200a fuse in there, please.