Dumb question

[tom lovinggood]

Hello--I have a question about my CUCV Blazer--are both altenators in the vehicle 12 volt or is one a 24 volt and the other a 12 volt? Thanks in advance

Tom Lovinggood

 

[firefox]

Both are 12 volt. It would be a good idea to download the CUCV manuals from this site.

 

[MarcusOReallyus]

TMs are here.

Other useful manuals are here.

Helpful thread sticky is here.

Lots of good reading there. Do make sure to read ALL THE WAY THROUGH each thread, as there are a lot of ignorant comments that (mostly) get corrected later. For example, on the "Can someone explain isolated ground to me?" thread, the very first response is completely wrong. (It's a classic case of a little knowledge....)

But back to your question: As mentioned, they are both 12v, but they are slightly different than a standard alternator in that they are both isolated ground. Only the passenger side needs to be isolated, but to keep supply inventories simple, the Army made them both isolated. The driver's side is grounded normally to the chassis by a ground cable, instead of being grounded through the case like a normal alternator. The passenger side must NOT be grounded to the chassis. Smoke and fire and melted links will be the result. Fun stuff!

 

[Guyfang]

The only dumb question, is the question not asked.

 

[tom lovinggood]

Isolated ground alternator

Hello--the alternator on the driver's side of my "86 M1009 is making a grinding noise while the engine is idling. The noise goes away when I put the blazer into Drive. I am anticipating replacing this alternator in the very near future. Any hints on the replacement process? Thanks in advance

Tom Lovinggood

 

[porkysplace]

Unhook batteries , remove alternator , replace alternator, hook batteries back up .
Have you downloaded the the TM's that were provided to you in this thread
Dumb question

TM9-2320-289-20.pdf
TM9-2320-289-20 Unit maintenance manual for all variants CUCV.

Start reading at page 243 of the above posted pdf for step by step instructions.

 

[tom lovinggood]

Porky--ok thank you--sorry for the question--I am a novice in the field of CUCV;s.

 

[Rutjes]

The passenger side must NOT be grounded to the chassis. Smoke and fire and melted links will be the result. Fun stuff!

That explains something that happened to me recently. I was in a rush changing belts recently, forgot to disconnect batteries and loosened the alternator. It grounded to the engine/chassis and there was smoke everywhere (engine crud?) and I saw a wire glow up like a light bulb! I almost **** my pants, disconnected batteries as fast as I could and emptied the fire extinguisher on the engine bay. I couldn't find anything else burned or otherwise damaged besides that 1 wire so I guess I got very lucky!

In short, be very careful handling that alternator!

 

[tom lovinggood]

Rutjes--thanks for the advice I don't want to become a human lightening rod.

 

[aleigh]

The only dumb question, is the question not asked.

Unfortunately the corollary would be "The only dumb answer is one not provided", and we know that not to be true...

 

[Drock]

The fact that it goes away when you put it in drive is suspicious? I'd remove the belt, then start & run it to see if the noise goes away.

 

[doghead]

Merged your two threads.

Next time please continue in one thread, like this.

And title descriptively.

 

[tom lovinggood]

the bearings are probably shot in the alternator and that is why it makes the grinding noise. It still produces electrical power, however, but the grinding seems to be getting worse. It just make sense to replace it, as it not that expensive.

 

[doghead]

Replacing the bearings should cost less than 10 bucks.

Correct isolated alternator cases are far and few between.

Do NOT give up your oem alternator. Rebuild it.

 

[tom lovinggood]

Doghead--I checked the section on ebay on CUCV parts and there seem to be several isolated grounded alternators for sale--all in about the $200.00 range. Are these not what I am looking for?

 

[doghead]

Do not get rid of your oem alternator, rebuild it.

For about $40 total, you can rebuild your original alternator.

New, Chinese copies are not a good choice and many people have bought them only to find they are not isolated ground and burn up the wiring, because they did not test it first.

 

[porkysplace]

Tow4 has rebuild kits listed in the SS classifieds.

 

[MarcusOReallyus]

Tow4 has rebuild kits listed in the SS classifieds.

Yep, and it's brain-dead easy to do.

 

[Guyfang]

That explains something that happened to me recently. I was in a rush changing belts recently, forgot to disconnect batteries and loosened the alternator. It grounded to the engine/chassis and there was smoke everywhere (engine crud?) and I saw a wire glow up like a light bulb! I almost **** my pants, disconnected batteries as fast as I could and emptied the fire extinguisher on the engine bay. I couldn't find anything else burned or otherwise damaged besides that 1 wire so I guess I got very lucky!

In short, be very careful handling that alternator!

Nothing like OJT!

 

[Barrman]

Check the bolts that hold the cast iron bracket holding the drivers side alternator to the engine. Then look under the #1 cylinder exhaust behind the power steering pump at the block. There should be an extension of the power steering pump mount bolted to the side of the block with a single bolt. Make sure that bolt is there. If it isn't, lots of idle noises come from that bolt missing. Power steering bracket breaking will also come from that bolt missing.

I know you wrote it is a grinding noise, but it going away when put in drive got me thinking of other causes of a noise.