hey so I have a 6.9 idi in a 1990 truck. It is not the same engine for the truck but the truck prior to was a diesel.

Question 1:
I converted the 6.9 to a serpentine with all the accessories from my 7.3l. how do I convert the older style wiring harness to the newer for the alternator?

-the alternator I have has two plugs. one plug has 3 wires (one of them y's and goes into its own separate plug) plus the power wire that screws into the back.

Question 2:
The wiring harness plugs into the other style but I am sure the wires don't necessarily match up. Does anybody have a wiring diagram for what wires I need to splice to which?

 

I have some manuals I can email to you might help. I got them on here. I will look at my setups later. I have the '83+'89 with factory wiring and the '90 has a '93 engine which I still have the donor truck. Maybe I can let you know what I see.

 

do you still have the 7.3 harness?

 

Here are a couple of links on 3G alt conversion. Describes how to wire it up, should about cover it.

https://www.ford-trucks.com/forums/8...-pictures.html

Fuel Injection Technical Library » 3G Install Tech

 

yeah thanks I had found those 3G conversions articles helpful. I didn't have to convert this alternator when it was on my 92 I am under the assumption that it might have already been done by the prior owner. I ended up taking a 7.3 harness and she plugs right in. The truck was a 1990 so it had a 7.3 in it originally with a 6.9er in her now. Fired up today..was thrilling

 

Hmmm any tips? I plan on doing this same thing but it will be in an 89