Aux Generator Questions

unorthodoxneon · May 1, 2007

Well this weekend i plan on taking on the challenge of fixing the alternator on the aux gen on the truck we have. I plan on taking it out and taking it up to an alternator rebuilder and then put it back it.

I have a few questions and hopfuly someone can help me.

1) Any one have an alternator rebuilt? What is the common cause?
2) What is the part number for the belt for the alternator
3) Anyone do this before, have any tips and trick for this.

I've taken the front panel, the top and the side thats close to the front of the truck off, and the alternator looks like a real pain to get to, but i think with the right tools and time i can get it out. Also after checking out the generator i noticed that a few fuel hoses are cracked so i will be replacing that as well. I also will be changing the oil, fuel filter, oil filter and air filter. Anyone have anymore suggestion what i may do or look for while taking the time to work on this.

Thanks in advance. Gas prices are way to high to be idleing and the generator works just the alternator is shot (for what i can tell).

Oh, and not to mention i run for fleet owners. Cant ask for a better driver :+

(quote for old post about part numbers for aux)
As far as filters go you can get those at NAPA
Air filter 2716
Fuel filter 3389
Oil filter 1034

Kevin_Sue · May 1, 2007

I do not know about aux generator alternators but with auto they usually just replace the failed part at the rebuilders then a short time down the road the next componet goes bad. Is it possible to call a couple facilities that install and repair APU units and find out how much a factory rebuilt is. Also mack sure they rebuild it not just replace failed componet. Just an fyi in a mercury grand marquis i owned I replaced the alternator with a NAPA rebuilt. This should have been a high quality part since NAPA is first class parts. In 2 years time I had installed 4 Alternators. Parts warrantied Had a repair shop make sure failed part was not caused by another componet. IE battery or starter. WAS assured it was a failed part. Was surprised abut 4 bad alternarors in 2 years since several years ago my family owned a NAPA parts store and auto repair shop and I then would have placed as much faith in the quality of their rebuilt parts as new. Shop owner said things are different now and they do not do complete rebuilds like they used to. I had availability to buy a new alternator. Take off part from a company that builds busses. Installed Alternator problem solved. What I am saying is try and make a couple phone calls get prices. check with maker of APU. If you find a rebuilt ask if it is a complete rebuild ( all componets that can fail are replaced). or is it bench tested and only failed componet replaced. Warranty asside if part fails it is a lot of work to swap out you may not get reimbursed for the time.
Good luck

greg334 · May 1, 2007

1) Any one have an alternator rebuilt?

Yes I have several times, no biggie. Did the Delcos and Chryslers myself and the fords I had a company do.

What is the common cause?

Usually it is the diodes that will fail, the second thing is the brushes but with internal regulated ones, the regulator cr*ps out because of the heat.

2) What is the part number for the belt for the alternator

Who knows. The best thing to do is to take the belt to an auto parts store and have them measure it with a belt measuring device, not a tape measure (because most of the parts people today are like a lot of the mechanics and McDonalds hamburger flippers). Also remember to make sure that the size (width and depth) of the belt is the same.

3) Anyone do this before, have any tips and trick for this.

Yes it is easy but just remember how to put it all back. Don't be like the service tech that worked on my reefer, 'here are your old parts back and some that I could not figure out where they went'.

I haven't looked at too many APUs (about 6 of them so far)but I am of the opinion that they really need to start using truck parts in their products. I mean, ok I have had a few alternators fail in my time but the ones that I really depend on (my dodge trucks) never failed because they were made for a harsh enviorment with lots of heat. The APUs i have seen use a standard light duty alternator, which makes me wonder about what are they trying to do, save money? Know what I mean?

rollnthunder · May 1, 2007

The alternator on a AUX gen is the same as one on a small block chevy.I worked for a auto parts store for several years and when mine started givin me problems i took it off and took it in to be tested but with todays testers its done by make model year.I ended up just crossing the #s stamped on the housing and got a new one for under $30

Doggie Daddy · May 1, 2007

Neon,do you own a boat? These AUX generators make GREAT boat anchors.They are not much good for anything else I am sorry to say.DD.

unorthodoxneon · May 2, 2007

Yes DD they do make good boat ancors or if you have a really big piece of paper a good paper weight. But with the price of gas, and the ability to sleep without all my teeth falling out from and idleing truck i've decided to repair the part.

Greg, since your from the Metro Detroit area as i am you probably know the place i'm taking the alternator too. Bill Suburban (Gratiot & Common, Roseville). I've had multiple alts done there. Known of people that took them there. And they've been around for along time and really friendly and knowledgeable (even when i ask really stupid questions).

I'll probably have them do a complete rebuild as stated to make sure that something doesnt fail down the road. I will probably have the big alternator rebuilt as well (why not right?)

The aux generators are no longer in service. My fleet owners had one replaced on another of their truck and they paid hundreds of $$$'s and actually have no interest in having this one fixed at top price. So i decided to take on the task myself (mind you i've went to college for automotives so i'm semi-handy with a wrench).

Also i've looked inside the box of the generator and the alternator is in the back and kinda hard to get to. There really isnt much air flow for the alternator let alone getting a socket in there. But come next monday it will be fixed unless there is something else wrong with it but i cant see how the electronics for the generator would cause the alternator to not work properly. Also for the belt its a very small belt and heard that i would have to take up to a small engine (lawnmower) shop to find a belt.

rollnthunder · May 2, 2007

You can get the belt at any auto parts store if you take the old one in and have them measure it.As of these being a boat anchor i dont agree.Mine is 7 years old and still works fine.I keep the oil changed and belts checked weekly.I have put a alternator on it but it only cost me $30 at the auto parts store.Like i said its just a alternator that fits on a small block chevy.Im sitting in Norfolk,va right now and its in the upper 80s and i have the air going nice and cool in the truck.

unorthodoxneon · May 8, 2007

14 hours later, bloody knuckles and bumps on our heads. We have a working generator. Had a bad alternator and just went and bought a rebuilt one as the one that was in there was shot and needs alot of work to rebuild. So i choose time over money. We also put in 3 new 1000CCA batteries as the old ones at somepoint froze. The part numbers i listed above are correct for belts and oil filter. The fuel filter isnt the right one as listed. I dont know what the number is to the fuel filter though. Plus note that the oil hold 1.5 gallons. If your oil is abit low there is a kill switch that will cause the generator to not work if there isnt enough oil pressure.

So now with new batteries, and a working generator i am very happy with the out come. I hate idleing the truck especially with the price of fuel now.

If anyone has any questions on how to do this dont be afraid to ask any questions. Its a major pain but if you have the patients, tools, and time its easy to acomplish yourself and not have to pay a shops crazy prices.

ConfusedMuse · May 16, 2007

I am curious what shop hires a mechanic that can't put ALL the parts back correctly on a reefer? Please do us all a favour Greg and post the shop.

greg334 · May 16, 2007

ThermoKing Redford, MI.

unorthodoxneon · May 21, 2007

Well for an update. It worked good while it lasted. A few days ago it would sound like its going to die and then act normal and kept doing this for a while. So i figured it was the wire comming apart again. I checked the wire and everything looked ok. So now it no longer runs.

Next i'm looking for a nice long chain to hook it up to for a boat ancher. }>

davekc · May 21, 2007

Sounds like a fuel pump or selonoid. Other thought is it is drawing air into the fuel system somewhere. Try and rebleed the system. If your tanks ever got too low, some air might be in the engine.
Just a thought?

Davekc
owner
22 years
PantherII
EO moderator

cliffn · May 21, 2007

Our generator is an older Pro-Heat. It has two fuel filters, one is an inline filter and the other is a small canister type. More than once when it has symptoms as you describe (cutting out then running again) it has been solved by replacing the fuel filters. If yours has a similar setup it certainly would be worth a try. Make sure to fill the filter(s) with fuel if possible so you do not trap a lot of air. Even at that you may have to start and restart two or three times to get it worked out.

Just a thought. Good luck.

Cliff

Cliff and Tami
D Unit Team
18 Wheeler Team 8 years
D Unit Team 4 years:

unorthodoxneon · May 21, 2007

I never really "bled" the system. What i did was just take the hose off and have my g/f keep hitting the starter until fuel squirted everywhere. Then i put the hose back on the motor and hit a few more times and it started like a champ and ran for a few days. As far as the filter i couldnt find the exact one so i found one that was close so i used that. So atleast the 1 filter has been changed.

What i need to do is take that hose back off to see if there is fuel comming pumping. If not i'm going to have to check the relays to see if there is an issues along those lines. Or the fuel pump just went out.

If i come up with any solutions i will keep everyone up to date as i know alot of people are running with the Aux generator and may run into this issue.

rollnthunder · May 21, 2007

How many hours do you all have on your AUX?I have about 4500 hrs and dont have all the problems.Mine was put on the truck in 2000.But this truck and Aux was maintained very well.

unorthodoxneon · May 23, 2007

Well a quick glance in the back of the sleeper it shows a number thats 8XXX.X Hours. So after a quick calculation. This generator has almost (or did) idle for a whole YEAR!!!!

unorthodoxneon · Jun 7, 2007

Well as an update. I figured out whats wrong with the generator now. The "plunger" that opens and closes the choke seems to be bad. If i have my g/f try to start it from the inside and then push the plunger in a bit it starts up and runs like a champ.

Has anyone replaced this or know how much it may cost. I can get a part number and call but i'd rather ask here.