2nd alternator

[Dingo509]

Im trying to fir a second alternator on my 4.0 and am not having much luck, but i have an idea. but fis=rst i have a/c and don't want to lose it, and i already have a york next to the stock a/c compressor. The engine is a 91 but has a 99+ intake on it so goes by the 99 belt routing. IIRC there is a bracket to mount an a/c compressor below the intake? but i can't remember what it was from. It would be very easy to adapt the a/c bracket to hold an alt. but i can't remember what it was from. Any ideas? i have the belt routing all figured out using a single belt (seperate belt for the york) with sufficent contact area.

Dingo

 

[ren]

Try looking at the WJ grand cherokees. I just did a brake job on my neighbor's 2000 model with 4.0, and the A/C comp. is mounted BELOW the P/S pump. If I am not mistaken, the WJ 4.0 is the same as all the other 4.0's.

 

[Pete M]

A second alternator? May I inquire as to why?
Jeep on!
--Pete

 

[ren]

Maybe to use the factory one for normal power, and the second one for a welder, maybe? That is how my '73 CJ-6 is set-up: Pass. side is main power using GM alt., and the drivers' side useing Motorola for OBW. Uses factory brackets from different age jeep six cyl. motors.

 

[Pete M]

What about a higher output alternator? When my old alt died I bought a 170amp alt to replace it so I could power a future underhood welder. 170 amps is a ton of juice. I would like to raise the alt's location up some of course...
Jeep on!
--Pete

 

[VegasAnthony]

http://www.naxja.org/forum/showthread.php?t=64215&highlight=alternator+welder

http://www.naxja.org/forum/showthread.php?t=63936

 

[Dingo509]

Maybe to use the factory one for normal power, and the second one for a welder, maybe?

BINGO, we have a winner. that's exactly what im trying to accomplish. I have drawn up some wiring schematics that will enable me to switch the second alternator to a welder and back again.

2 main points here;

1. the higher amperage the alternator puts out, the less amps it puts out at idle, so basically a 210 amp alternator will put out 210 amps at a very high rpm, but will only put out like 50 at idle, where as a 90 amp model will put out almost full capacity at idle so 2 90 amp (or 1 140A and 1 90A in my case) will put out more at idle than a 210 amp ever will.

2. simple, redundancy if one fails the other will get me home.

Dingo

 

[ren]

Hey Dingo, try using the Motorola alt with the EXTERNAL regulator. That way you can go ahead and set-up the regulator wiring harness to hook up to your jeep when need for power, just do not hook up the reg. unit until needed. The Motorola alt. is easy to set-up for welding. Try looking at this site-pirate4x4.com/tech/on-boardwelder/index.html Should be pretty self-explanatory. HTH Ren

 

[Dingo509]

Hey Dingo, try using the Motorola alt with the EXTERNAL regulator. That way you can go ahead and set-up the regulator wiring harness to hook up to your jeep when need for power, just do not hook up the reg. unit until needed. The Motorola alt. is easy to set-up for welding. Try looking at this site-pirate4x4.com/tech/on-boardwelder/index.html Should be pretty self-explanatory. HTH Ren

Thanks but i've done alot of research on these things, including that site. but i have like 4 spare XJ 90A alternators lying around so that's one less thing i have to find in this town. the only issue i'm having is figuring out where to mount it.

BTW any chance you can get a picture of the a/c bracket on that WJ and the belt routing on the drivers side of the engine? I actually thought of just moving my a/c compressor to the WJ location and then using the original a/c location for the primary alternator, to keep it up out of the water, and then the original alt location for the second alt/weldernator. does that make sense?

wasn't there something else that used the under manifold a/c location. Maybe RHD XJ's?

Dingo

 

[old_man]

Just a tip. If you need to route the belt so that the water pump turns backwards. There is a reverse rotation pump available.

 

[Dingo509]

Just a tip. If you need to route the belt so that the water pump turns backwards. There is a reverse rotation pump available.

Ah yeah.... from the 258 with the serp belt, right? i'll keep that in mind.

I think i have the belt routing figured out without it though i'll try and draw a crude picture and explain later tonight. then everone can tell me if they think it will work.

Dingo

 

[old_man]

Actually I was thinking of the 2.5L w/ Vbelts. They look exactly the same on the outside but the guts are set up for counter rotation.

 

[ren]

Make sure to check the snout height on the water pump, the pump off my '84 2.5 motor is WAY too tall. I found that out when the water pump died in the MJ about a week ago. That was really irritating to find out, but hopefully, you can find one with the right length snout. Not to be argumentitive, but I seem to have a habit of getting the screwball Jeep stuff, that just HAS to be different from everybody else - my '84 XJ has a carbed. 2.5, auto tranny AND 3.54 gears, for example. So much for the " 2.5 four cyl. motor XJ's all came with 4.10 gears" myth. Oh yeah, NO disco axle, but has CV shafts with what I think is a 207(?) x-case.

 

[Dingo509]

Okay this is what im thinking for the belt routing this is looking at the engine from the front.

The A/C, Alt, Fan and Idler on the pass side are all 91-96 applications the P/S and idle on the driver side are 99+ applications. The red belt would be the single serp belt whereas the blue belt is for the york on a kilby bracket. as far as i can tell this would still use the 4.0 water pump as the rotation does not change.

Think its possible?

Dingo