Group 31 and Gen 3 Alt upgrade

[jayro88]

Hi folks,

So in the next couple weeks I am planning on upgrading the batteries in my '88 e250 to a pair of group 31's and swapping to a new Gen 3 alternator. I found some good write-ups on this and it looks fairly simple.....but I do have a few questions:

1. With mine being a van body, where are have other mounted the fuse in the charge wire?

2. I believe the stock charge wire runs down to the starter to connect to the positive battery cable. Can I simply run the new charge wire directly to the positive post on one of the batteries instead.

3. I currently have post batteries and battery cables. I have the option to get Group 31's with posts or with studs. It wouldn't be too much extra work to cut off my post connectors on my cables and swap them over to stud connectors. I am thinking this would make things easier in the future etc. Is this recommended?

4. While I have the batteries out I want to bypass the connector on the fender well that goes to the GP controller. The one with the 2 yellow wires that is known to corrode/melt etc. Can I simply clip the wires on each side of the connector and then connect them together? If so, what is the recommended connection method?

Thanks for the help.

 

[u2slow]

Group 65 batts may be more available/affordable or better warranty. CCA's are usually on par.

The alt charge wire can be run back to the battery, or any major distribution point.

I switched my cables ends to lugs. Seems to work out nicer. I like the military style connectors for post batteries.

You must be registered for see images

 

[jayro88]

Group 65 batts may be more available/affordable or better warranty. CCA's are usually on par.

The alt charge wire can be run back to the battery, or any major distribution point.

I switched my cables ends to lugs. Seems to work out nicer. I like the military style connectors for post batteries.

You must be registered for see images

Thanks. Interesting you said that about lugs as that is what I was wanting to move away from.

As far as 31 vs 65.....I have not found them to be on par with CCA. 31’s are 1125CCA vs 850 CCA on the 65s


Sent from my iPhone using Tapatalk

 

[u2slow]

Mine are 950cca (31) vs 850cca (65)... so quite close. Seems easier to find 65's with good warranty and prices. I have to pay full-bore for Interstate to get a 31 cranking with more than 18mos warranty.

You must be registered for see images attach

Where you mounting them? That can sway the size and post style decision. The 65's squat size made them easier to stuff under the seats in my E350 van (don't have anymore).

You must be registered for see images attach

 

[jayro88]

Mine are 950cca (31) vs 850cca (65)... so quite close. Seems easier to find 65's with good warranty and prices. I have to pay full-bore for Interstate to get a 31 cranking with more than 18mos warranty.

You must be registered for see images attach

Where you mounting them? That can sway the size and post style decision. The 65's squat size made them easier to stuff under the seats in my E350 van (don't have anymore).

You must be registered for see images attach

They will be mounted in the stock location under the hood. They are basically the same foot print, just slightly taller.


Sent from my iPhone using Tapatalk

 

[The_Josh_Bear]

Hi folks,

So in the next couple weeks I am planning on upgrading the batteries in my '88 e250 to a pair of group 31's and swapping to a new Gen 3 alternator. I found some good write-ups on this and it looks fairly simple.....but I do have a few questions:

1. With mine being a van body, where are have other mounted the fuse in the charge wire?

2. I believe the stock charge wire runs down to the starter to connect to the positive battery cable. Can I simply run the new charge wire directly to the positive post on one of the batteries instead.

3. I currently have post batteries and battery cables. I have the option to get Group 31's with posts or with studs. It wouldn't be too much extra work to cut off my post connectors on my cables and swap them over to stud connectors. I am thinking this would make things easier in the future etc. Is this recommended?

4. While I have the batteries out I want to bypass the connector on the fender well that goes to the GP controller. The one with the 2 yellow wires that is known to corrode/melt etc. Can I simply clip the wires on each side of the connector and then connect them together? If so, what is the recommended connection method?

Thanks for the help.

1. I have a pickup but put my mega fuse hanging vertically down off the starter solenoid post on the fender wall. Make sure the charge wire is not pulling on that fuse at all. I had one snap internally in a different position. Caused issues besides not charging the batteries.
1a. On that topic, when you swap your 3G in, make SURE the sense wire(yellow) is hooked up on the alternator side of the mega fuse. Mine was not and when the fuse broke my alt was charging almost 30 volts! Scared the hooey out of me. But once I got it back sensing alternator output instead of standing voltage it charged perfectly.

2. As another member said you can run it to any major distribution point. Battery or starter solenoid is good, just make sure that fuse is supported or under zero stress. And carry a spare, they are $5.

3. I recommend this if your terminals are older. In my case I used marine style post-to-stud converters but having the studs and wing nuts is so much easier and more convenient than the posts etc.

4. I also did exactly this. Cut, slide heat shrink over the wires, use 10-12 gauge butt connectors with proper crimping pliers and then slide the heat shrink over and heat gently with flame or a heat gun. And you'll never have to think about them ever again.

Happy wrenching!