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Unread 05-18-2013, 08:12 PM   #1
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DirtKar's Avatar
1993 YJ Wrangler 
Join Date: Jun 2012
Location: Nor Cal Sierras
Posts: 2,411
136A Alternator Upgrade

After installing a Volvo e-fan in my YJ I noticed that there was quite a bit of voltage fluctuation when the fan engaged. The e-fans take quite a bit of voltage on start up and I figure that must take a toll on the stock alt and wiring so what better project than a full electrical upgrade, right? The following contains some info I found on various sites as well as what I did. This will be a pic heavy thread and is not intended to be a be all end all but rather a what worked for me kind of deal. Disconnect your battery before starting any of this! After completing this makeover I can flip my headlights on (hi beam) and see no deflection in the voltage. When the fan kicks on the needle BARELY moves a tick and resumes its normal position at 14v.
Actual mileage may vary.

First off, the parts:
9' of 1/0 cable (red)
4' of 4ga welding wire (black)
#1 Bussmann fuse holder with rubber cover
#1 150a fuse
#7 1/0 copper lugs
#4 4ga copper lugs
#1 kit Marine terminals
Various size shrink tubing
#1 136a alternator
Solder, flux and map gas torch

I used a new 136a alt for a 98' Jeep GC w/v8. That unit fits a few different models and years and is a direct drop in for my YJ. It should fit these:

The 136a case was a bit larger in diameter than my stock unit but posed no problems with fitment.

The only mod I found necessary was the plastic lug on the alt faces the wrong way. Since I used such large gauge cable I had to trim the shield to fit the lug. No biggie. I used the shield from the old alt, trimmed it and installed it on the new unit. Also worth mentioning is that the new alt has a 7 row pulley vs 6 on the old- no problem. Just put the belt toward the back of the pulley or swap your old one over to the new unit. I left it.

The fixed post connectors on the bottom of the old alt will transfer directly to the new unit. I disconnected the hot lead to the old alt and clipped the terminal end off. I opted to put a rubber plug on the end and heat shrink to seal it. I may go back and remove that lead from under the fuse block or I may not...It's safe either way. It's tucked back into the corrugated loom.

Next up, new feed cable. I like 1/0 wire. Probably overkill but hey, I like it so there. First I flux the connectors then install the bare cable end and strike it with a punch to get the end to hold itself on. Soldering come next followed by heat shrink for both protection and support. I like building my own cables because it gives me the latitude to have them turn whichever direction I choose.

Next stop- 150a fuse:

From there we go to the top of the battery. I mention top because mine has front posts as well. From what I've read the front posts are not good for heavy loads ie: Winch, OBA, etc. I did repurpose my old smaller gauge positive cable to feed the fuse block via new connectors from the front lugs. This alone was a substantial gauge change from the little stock wire that fed the block previously.
Here's a shot of the old vs new. Beef!

Here's a shot of all of the cables intact. Included on the top positive are my winch lead, the feed from the alt and the new cable going to the starter. On the neg side is the winch neg, the welding wire going to the block and the welding wire going to the firewall. All connection areas scraped clean prior to making the connections. On the front lugs I have the feed to the fuse block and the feed to my front and rear lite relays. My e-fan is tied directly to the side of the fuse block and is protected via fuses and relays in the adjustable Hayden controller.

I think that about covers it. This job took me about 3 hours and I wasn't moving too quickly. It's definitely a doable job for anyone with some mechanical know how. Take your time, pay attention and have fun!

Originally Posted by Anticanman

Come on by! It's easy to network locally when you join a 4x4 club especially when all the clubs in your state are united and invited to each other's runs. You meet poor folk like me or run into guys that own some of the big companies you only aspire to order from and drool when you see their products. The great uniting factor is that we are all jeepers at heart and are willing to help each other out even if its just a little. That's what the jeep wave is all about: community. The wave is the tip of the iceberg.
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