4.0 B2 Swap Wiring Questions

[lowsinthe20s]

Looking for some help and detailed info on the distribution box wiring. I was given some info to swap all the B2 stuff to the 4.0 distribution box. I'm using the B2 Power harness that plugs in the drivers side and the 4.0 ECM harness that goes through the passenger side firewall.

B2 is an 89
Explorer is a 94

Does any one have pics of the underside their distribution box that shows what wire goes where? or detailed drawing a 5 year old can understand that would be appreciated.

I also don't understand how how the diode is wired.

I was also told there needs to be a wire run or spliced for the alternator. Any details on that?

 

[RonD]

Have you looked thru this article in the Tech section: https://www.therangerstation.com/te...to_explorer-_to_a_1989-2-9l_manual_bronco_ii/

That's your exact swap

There is also this Article: https://www.therangerstation.com/te...conversion-wiring-from-explorer-to-bronco-ii/

Good page to Bookmark here: https://www.therangerstation.com/tech/

Look in the engine section for more 4.0l conversion articles, thats where the above articles are located

Never done that conversion myself so can't help directly

 

[lowsinthe20s]

Yes, I have seen them. I'm specifically look for the distribution box wiring.

I haven't seen anything on here about that.

I'm not understanding the alternator splice either.

 

[RonD]

Alternator is fairly straight forward

There are only 3 wires to hook up

Larger wire or dual wire runs from Alternators B+ terminal(the one with stud/nut) to battery positive, usually on the starter relay(solenoid) on inner fender
Starter relay has two bigger posts, one post will have battery positive cable, thats the post alternators B+ connects to
This wire(s) should be connected to Starter relay post thru a Fusible link, which is just a special 6" wire that will not "burn" if there was a short, should already be setup that way, but you can add one, any auto parts place will have them, 12 gauge fusible link

Alternator will have a 3 wire connector
Yellow/white wire, white wire and green/red wire
White wire is just a short jumper to single spade terminal on the back of alternator

Yellow wire can connect to same starter relay post as B+ with another fusible link, 18 gauge
OR in 1994 there may be a 15amp "Alternator" fuse in the engine fuse box, would have the same yellow/white wire

The green/red wire is the ON/OFF switch for alternator, it goes to instrument cluster in the cab to the Battery(Charge) Light, its powered by ignition switch when key is on
When you turn on the key Battery Light comes on because Alternator is OFF
When you start the engine Battery Light goes OFF because alternator is now generating higher than battery voltage, if Battery Light stays on or flickers then alternator is NOT working

 

[lowsinthe20s]

Alternator is fairly straight forward

There are only 3 wires to hook up

Larger wire or dual wire runs from Alternators B+ terminal(the one with stud/nut) to battery positive, usually on the starter relay(solenoid) on inner fender
Starter relay has two bigger posts, one post will have battery positive cable, thats the post alternators B+ connects to
This wire(s) should be connected to Starter relay post thru a Fusible link, which is just a special 6" wire that will not "burn" if there was a short, should already be setup that way, but you can add one, any auto parts place will have them, 12 gauge fusible link

Alternator will have a 3 wire connector
Yellow/white wire, white wire and green/red wire
White wire is just a short jumper to single spade terminal on the back of alternator

Yellow wire can connect to same starter relay post as B+ with another fusible link, 18 gauge
OR in 1994 there may be a 15amp "Alternator" fuse in the engine fuse box, would have the same yellow/white wire

The green/red wire is the ON/OFF switch for alternator, it goes to instrument cluster in the cab to the Battery(Charge) Light, its powered by ignition switch when key is on
When you turn on the key Battery Light comes on because Alternator is OFF
When you start the engine Battery Light goes OFF because alternator is now generating higher than battery voltage, if Battery Light stays on or flickers then alternator is NOT working

Thanks. I'll give that a shot.

 

[broncc]

You can find a lot of useful information in my post here.

 

[SenorNoob]

I was under the impression that an 89 B2 was essentially plug and pray.

 

[lowsinthe20s]

You can find a lot of useful information in my post here.

Thank you!! That looks like great info there.

 

[89RanBrII]

plug and pray