Blowing Alternators

3

307Vintage

Member
This is a very unproud moment to post about. About two years ago I crossed the jumper cables on my 98 Runner. It, of course, blew the amp fuse, ruined the battery and shortly after I had to replace the alternator. Since that time I have replaced 3 alternators and the third is needing to be replaced as I search for solutions. I just replaced it 3 months ago. (A side note, after the event my dome light stopped working, until the following winter with 20 degree below zero days when it started working again, until the heat of the following summer when it quit and has not worked since.) Can anyone tell me what is going on and what I should look at? Thanks.
 
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I would set aside a few weeks of checking every wire & connection burnt wires and connections power & ground wires wires to fuse box every thing front to back. Or get a new wiring harness either one is expensive and time consuming.
 
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307Vintage said:
This is a very unproud moment to post about. About two years ago I crossed the jumper cables on my 98 Runner. It, of course, blew the amp fuse, ruined the battery and shortly after I had to replace the alternator. Since that time I have replaced 3 alternators and the third is needing to be replaced as I search for solutions. I just replaced it 3 months ago. (A side note, after the event my dome light stopped working, until the following winter with 20 degree below zero days when it started working again, until the heat of the following summer when it quit and has not worked since.) Can anyone tell me what is going on and what I should look at? Thanks.
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What brand alternators are you using? If it's not a denso alternator then that's your problem. Parts store alternators are known to have a very short life for us.
 
307Vintage said:
If it’s that simple I’m buying you a beer, or Fresca. Your choice. I’ll get one ordered today. Thanks.
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You can also order a brush set from Toyota for around 25 dollars and instal them yourself. And save some money.

As long as you have a Japan spec Phillips screwdriver it’s easy.


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19963.4lsr5 said:
You can also order a brush set from Toyota for around 25 dollars and instal them yourself. And save some money.

As long as you have a Japan spec Phillips screwdriver it’s easy.


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On the brush set, just call up the dealer and order a brush set? Or do you have a recommendation on an online vendor? Also the Screw driver, what is my starting spot on looking one of those up? Thanks fellas.
 
307Vintage said:
On the brush set, just call up the dealer and order a brush set? Or do you have a recommendation on an online vendor? Also the Screw driver, what is my starting spot on looking one of those up? Thanks fellas.
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The screw drivers are JIS Phillips. Probably Amazon for a set of those.


On the brush set. The dealer Probably be able hook you up with those. I don't have the part numbers handy

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Since you already have an aftermarket alternator I’d just get a denso from rock auto, the dome light could be totally unrelated just check all your fuses for corrosion, check the bulb socket in the light itself, and any plugs for corrosion
 
RandyBobandy said:
Since you already have an aftermarket alternator I’d just get a denso from rock auto, the dome light could be totally unrelated just check all your fuses for corrosion, check the bulb socket in the light itself, and any plugs for corrosion
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I just placed my order. Thanks
 
I agree most autoparts store ones are junk, I stick with Denso. I have a spare on my shelf that I put new brushes in...just if needed.

While waiting for your new alternator, i would go through and clean up all my grounds. There is one ground on the back of the engine to the firewall that often gets neglected and if I remember, its not a very large gauge wire.
I have run the big 3 on a previous 4runner. my current one I am just running an extra ground from the body to the alternator bracket, using the bolt that holds the dip stick tube., to the fender, same place battery ground goes to. I think I ran a 6gauge ( what I had around) . Figured cant hurt to have an extra ground..
I had seen something similar on a friends 4runner and he ran one to the air intake where there are other grounds connected ( driver side above front spark plug) but he went direct to his battery.
 
307Vintage said:
On the brush set, just call up the dealer and order a brush set? Or do you have a recommendation on an online vendor? Also the Screw driver, what is my starting spot on looking one of those up? Thanks fellas.
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If you ride a Japanese motorcycle you have one in your tool kit.

Reman Alts could be 70a or 80a. You need to identify which one before ordering.

When I bought my 97 SR5 project it had a CarQuest Alt and the cheep brushes in it lasted about 3 years before they were little nubs. It was the 80a model so I ordered a set from my local dealer. Their price was within 2 dollars of Internet pricing.

Edit: your CarQuest Alt is still a factory Denso Alt, it was just rebuilt by someone other than Denso.

All the OEM parts will fit in your CarQuest Alt.

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You can also run the higher amp alts in the older rigs if you want. Just make sure you keep track of it. Probably be best to swap out the fuse and charging wire. Granted its 10 amps more and both the higher and lower modules don't exceed the 90 amp fuse in the older 3rd gens. ( 70 and 80amp)

Just don't make the mistake of putting the lower amperage one in the late modules.

The alt fuses are 1996-1998 [100 amp] 1999-2002 [120amp]


Rule of thumb is stick what matches the rigs. :-)
 
Is the ground that goes from the firewall, by the heater valve, to the back of the passenger side head the only motor to chassis ground? I checked continuity on both that one and the battery to chassis and they were both good. But I am going to pull the motor to chassis and make sure it is clean.
 
307Vintage said:
Is the ground that goes from the firewall, by the heater valve, to the back of the passenger side head the only motor to chassis ground? I checked continuity on both that one and the battery to chassis and they were both good. But I am going to pull the motor to chassis and make sure it is clean.
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No that's the ground for the head.

Your negative terminal starter ground goes down the the block next to the oil filter. :-)
 
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