Alternator fun and games

[ALANSD]

A beautiful day here in Atlanta. I crawled under my MH after pulling the dog house covers off, and putting some light over the work area. I had disconnected the battery, pulled the old alternator, and attached the spacer to the new one, then tried unsuccesfully for about two hours to thread the bolt/line up the new alt. and mount it.
Sitting on the ground behind the curb side tire between the steering damper and radiator support and not being able to thread the bolt in. My new neighbors heard some choice epithets.
And I was out of beer besides!!
After major back/leg cramps, I finally managed to get the end of the bolt to catch, then the unit got stuck so I couldn't plug the wires in! It seemed to be wedged in too tight to move. I loosened the bolt again, no luck, had to pull it off all the way. By this time it was getting dark and the mosquitos decided I looked like dinner.
Any great ideas to make this job next weekend a bit easier?
I have done a few alternators in the past never had so much trouble fitting it. Oh yeah its a Delco exactly like what I pulled off but 135amp version. Also-- think a new battery wire is a good idea? The one on there doesn't look too dried out...

[john hd]

alan

you are not using enough "lubrication"!

quote: "And I was out of beer besides!!"

john

[Tom Nugler]

Having been in the car biz for about 35 years I can relate to your pain. While I am not familliar with this powertrain package I have found many alternater mounting brackets have a threaded insert that MOVES when the mounting bolt is torqued up so as to eliminate play and provide a good ground. Try installing the bolt, sans alternater, and tapping the head end to push the insert back or forth to gain some clearance. Good Luck and have a cold one for me.

[74Argosy24MH]

Also-- think a new battery wire is a good idea? The one on there doesn't look too dried out...

What size wire is on there now, 10 ga? You need at least 2 for an alternator that big.
Compare the length and case diameter and the position of the plug and the mounts on both alternators. The case halves will rotate to 4 different positions for different vehicles.
Is the top bracket on? Hang it from there first then line up the bottom hole. There are other holes in the head the same size, make sure you are getting the right one.

John

[Astrodokk]

Alan, now you know why I PAY to have it done LOL! Albeit through the nose.

As an after thought, beer has been known to alter one's control of the lumbrical muscles of the hand phalanges. I would recommend using Michelob Ultra, which is low in carbs and since you may think you're drinking carbonated water, psychologically enhancing as well.

[ALANSD]

John the case looks to be set up just like the one I took off. You say that I can take off the back and rotate it? ...if so it could make the plugs more accessible. I hung the tension-mount bolt first, but I was afraid I might strip it with all the movement to get the bottom one line up. A few sprays of wd-40 seemed to help get the bolt to start right.

Not sure what gauge wire is on there but I would bet it is not as thick as a 10 ga. The dealer sells a special cable cut to whatever length needed for 150 amp and over, if it makes sense to, I can order it as well. The battery cable goes to the junction box then to the isolator?

[ALANSD]

here is the cable description

"100% New alternator power cable. This new four gauge commercial quality cable is 6 ft long and comes with crimped 5/16" copper terminals enclosed in heat shrink tubing. The entire cable is also covered with split loom to protect it against shorts. We require this cable on all alternators 150 amp and larger. This new cable can also increase amperage output and decrease resistance to the battery." $25.00

[74Argosy24MH]

You can rotate the case but don't take the back off or the springs and brushes will come out. Pull the 4 bolts holding the halves together, wiggle it a little to loosen it and rotate it to the position that works. The brushes are only about 1/4" wide so if you move it that far back they will come out. If they do it is only a straightened paper clip to reinstall so don't worry.

Check Autozone for battery cables, less than half that price but no heat shrink. Get some split loom tube and pocket the change. They should have them with lugs on each end.

I would put in the top mount bolt first. Look at where it was from the mark on the bracket. Tighten it so it is snug but you can still rotate the alternator. Make sure the spacer is right (or leave it a little loose) so it doesn't force the pivot bolt to misalign. Use the WD40 liberally and wire brush the threads if they need it. It has probably been a long time since this was removed. If you have some antisieze (or grease) smear it around inside the bottom alternator mount hole. All that contact between the bolt and aluminum makes a mess, I have seen those big long bolts twist right off. That is not fun.

John

[wb13798]

i replaced mine from the top. i upgraded to a 100 amp .
i took the top bracket off and inserted altenator in the cavity and screwed the lower monting bolt in and tightened. installet top bracket then belt tightened and havent had to do any thing. took and hour. but if you are trying to install from the wheel well that should be a bit easyier. i would get someone to hold the altenator up from top side whilr you monkey with the bolt. lol
al

[ALANSD]

seemed to be hard to reach from the top, but I will try to get my assistant (read spouse) to hold it while I screw in the bolt.

While at it I noticed a hose clamp or two that need replacement ..and the carb could stand another cleaning. and....

[59toaster]

If your having that much problem getting it back on you may need to loosen up the mounting bracket the bolt passes through. Might even neet to loosen the bracket the alternatoro tensions against. It may be slightly cocked to the bolt hole in the front of the head.

GM alternators usualy go on pretty easy. Something has to be out of alingnment.

[ALANSD]

yeah I thought having the spacer tight was a good idea. Now that I have backed up a little I find a few other things that need attention anyway

[ALANSD]

thanks for the advice, leaving the spacer a bit loose and using lots of wd40, and some non locking lube on the bolt the alt went on this morning easily. Had some trouble reaching the wiring afterwards with my less than long arms, but all went well. Now 2 questions...
I replaced the wire from the alt to the isolator with a 4 ga. cable, and I want to know what is the relay(?) on the left of the photo for?
Connected to the isolator and then onward...
Is it in need of replacement now that I have a 135amp alt?

Also I am buying a new isolator as mine is a 95 amp. If I run it meanwhile wiht the 95 amp will it fry the isolator? Or should I bypas it for now, and run it with out.
I should have a 150 amp or higher rated isolator in a week or two. Thanks all.
( the yellow wire is the old wire to my rear air bag compressor that I have replaced)

[PeterH-350LE]

Originally posted by ALANSD
... I want to know what is the relay(?) on the left of the photo for?
Connected to the isolator and then onward...
Is it in need of replacement now that I have a 135amp alt?
.....

That's a fuse, probably 30 amps. No need to replace it, but good to know its there for future trouble shooting.

[74Argosy24MH]

I want to know what is the relay

Looks more like a circuit breaker. How many wires, just the 2 cables? If it is a relay there should be at least one small wire for control.

If I run it meanwhile wiht the 95 amp will it fry the isolator?

As long as you don't drag the batteries down it won't take that much to recharge and shouldn't hurt the isolator. If you are worried move the battery (cable) that had the most use to the center terminal and the isolator will be out of that half of the circuit.

John

[dinoburb]

ALANSD,

The item is a circuit breaker as John said. It is probably a self-resetting breaker. I would check the amperage rating so you know what is considered an overload by the original installer. If you are increasing the output of the alternator and you are increasing the carrying capacity of the wiring; it stands to reason the CB might be too low a rating and cause problems of its own. Never hurts to check!!

Take care.

[ALANSD]

muchas gracias mi amigos. Of course I want to start her up and run it and see how I did, I just didi not want to fry the isolator. I will try disconnecting the coach battery before I do that as it is on the list to be replaced.

[wb13798]

not to worry alan. you dont need to replace any thing . the cb is a fifty and it will trip before you fry the isolator. the fact you inslalled a 150 amp alt doesnt mean you will generate 150 amps
if your batterys go dead or short then you might be in trouble the alt will try to pick up the load and fry the iso and wiring. i loked at a 63 310 that had the starter cable short to the frame and it made a mess, but didnt kill the alt. the cb should have tripped but didnt.

[ALANSD]

Well I cranked 'er up today and the voltage meter was smiling at me 14+ volts with every light/radio/signal/etc on. Great!

I am looking at getting a 200 amp load isolator from a friend, so I hope to get that on in a week or so.
Now I can get back to playing with the rear air bags.