Rebuilding a 3G alternator (2024)

Reed #433081 December 22nd 2010 6:32 pm

Hickory Flat, Jawga

10-4.

I haven't noticed any trouble with the 'puter missing the pump. The O2 sensor is before the Cat so I don't know if it makes any difference as far as the ECM. I left all the solenoids in place and plugged the vacuum lines.

Now if you wanted to remove the EGR valve....the computer would go home to Momma!

CatFish #433082 December 22nd 2010 6:38 pm

Fircrest, WA

Yep- the EGR is staying. I have seen kits that you can install to fool the computer into think the EGR is still present, but I think the EGR allows for greater timing advance so I want to leave it to help with fuel economy and gas mileage.

I need to double check the routing on the air pump. I know the pump injects air right at the back of the heads, so it is upstream of the O2 sensor. I need to do more homework before I just rip it out.

Superbeast #437992 January 13th 2011 10:12 am

NY

GEORGI #438024 January 13th 2011 12:37 pm

Fircrest, WA

Absolutely! All the info you need can be found at:

http://www.thewebwheeler.com/forums/showthread.php?t=1918

You can get NEW alternators and all the miscellaneous install parts at:

http://rjminjectiontech.com/

I got the Megafuse kit, the battery terminal adapter kit, and the wiring adapter from RJM. Great quality, fast shipping. You will need to play with pulleys and probably spacers to get the right one for your application, but you can get a 130 amp stock alternator for your van. They even can be retrofitted to higher amps, but I doubt you would need it.

UPDATE:

I got my 3G alternator installed. I ended up having to buy a new one from Napa, but the hardest part of the install was grinding the bracket for clearance. I did have some trouble with the pulleys. On a stock 1989 serpentine belt system, you have to use a small diameter pulley. The larger pulley that came on the new alternator I bought just would not work. I tried another small diameter pulley I had but the offset was wrong and when I snugged it down it tightened against the case and wouldn't move. Fortunately, I was able to re-use the pulley from my old 2G alternator. Be prepared to play with pulleys and spacers to get this to work right.

Reed #438492 January 16th 2011 3:41 am

Dundee, Michigan

Reed, how about some pictures of this? An upgraded alternator is quite high up on my list of things to do, and a successful installation is well worth documenting! We're all adding more electronics at a heady pace...

Did you set yours up for remote voltage sensing?

Ram4ever #438493 January 16th 2011 5:53 am

Dundee, Michigan

Good heavens Reed, I was just checking out the prices that rjminjectiontech site you mentioned lists for their weatherpack connectors, terminals, and wiring products, and they made my head spin; that guy offers some kind of deals!

Now I'm lusting after that 22-pin weatherpack bulkhead connector!

There was a real pearl of wisdom in there too, under his "Why don’t you sell 200amp alternators?" section he stated:

"Back in the early 1980′s Jim Vance of the Gates Rubber Company invented serpentine belts. The wider serpentine belt transmitted more power to the alternator, allowing for higher electrical output. However all belts have their limitations.

a single V-belt can only generate ~95amps before it will slip.
a 6rib belt can only generate ~180amps before it will slip.

There is no reason to have a 200amp alternator if it will only produce 180.

... This is why I only sell the dual V-Belt pulley. You need to run BOTH to get the rated output.

For a while Ford offered a 215amp alternator made by Mitsubishi on its diesel ambulance option. However this alternator had an 8rib belt, because it's required to generate that much power."

-That's really useful data to have available. Guess that puts a limit on how big an alternator it's worth putting in my van with a dual-V pulley like I've got.

Thanks again for the tip Reed; it's a real treasure!

Ram4ever #438516 January 16th 2011 12:21 pm

louisville, ky

Hey I'm re-wiring a 61 econoline right now for a local beer company and in my search for information found this. it wasn't relevant to me because the van has a tuff stuff one wire alternator but for anyone with a simplified system looking to upgrade this atlernator it could be helpful.

Reed #438525 January 16th 2011 1:14 pm

Breslau,Ontario, Canada

Ken_Hopcraft #438607 January 16th 2011 9:02 pm

Fircrest, WA

(1) No pictures, since this new alternator looks basically the same as the old one. Nothing very fancy.

(2) I didn't set it up for remote voltage sensing, I don't know how. Plus, this swap renders the factory ammeter innaccurate, so I need to find a workaround for that.

(3) This was on a Ford, so the upgrade isn't applicable to Dodges. However, you can upgrade to the factory 120(?) amp alternator using boneyard parts. Look for a van that has rear window defog and grab the alternator and all the wiring running from the back of the alternator to the (+) battery cable and the bulkhead connector. The high amp alternator uses fatter wiring due to the higher amps, and it uses a different connector on the field terminals. You will need the alternator, brackets, and wiring.

(4) To plug the holes in the back of the heads, you remove the crossover pipe, snip the pipe away from the part that has the bolt pass through it, flip the part with the bolt over so what used to face the head now faces the air, put the bolt back in.

So far, the 3G alternator has been working great. Other than the loss of the factory gauge, I am completely satisfied with it.