3G upgrade in an 85?

[RsStanG1987]

Anyone have write up on how to do it? I searched but only the 86-93 method comes up.

 

[Celeb]

Found this diagram that you might could use.

 

[jrichker]

3G install into an 85 or earlier Mustang:

I would recommend the addition of a 2 amp fuse on the Light Green/Red wire that goes to the switched ignition.
I would use a maximum of 150 amp fuse for the output wire that connects to the starter solenoid.

 

[RsStanG1987]

Now heres my question.. What do i do with the stock wires??? Can i cut a pigtail from the junkyard and splice it in. I need to know what color does what on my wiring harness. I also think my car may have an external voltage regulator.. Does this matter. Also is there a way for me to wire my msd into this so when i kill the key my car actually shuts off.

 

[RsStanG1987]

bump

 

[RsStanG1987]

Ok so basicly i need to run 2 new wires???

 

[bredaned]

so can i do away with the plug thats got the two black and yellow wires and one white wire

 

[Darkwriter77]

You'll run a 4-gauge (or larger) from the alternator post to the battery side of the starter solenoid and the green to a switchable 12-volt source. That's it. The others get routed as shown above. It's pretty simple.

 

[RsStanG1987]

whats near the alt under the hood of an 85 where i can run the green wire? Is there a post on the starter selonoid thats hot while cranking and while the car is running?

 

[KyleEBK]

i had a similar issue with doing the 3g upgrade in my 84 svo mustang it still had the voltage regulator on it

I actually ran a wire into the fuse box and hooked it into the blower motor slot, it went hot in run.

all it does is "excite" the alternator to tell it to start charging

i pulled the regulator off and cut the plug off and wired it all manually

worked good for well over a year now


you may not want to do it that way but i couldnt figure anything else out, not sure if ur car has a blower motor fuse slot tho... ill looka round for the link to my issues i actually had to go to a tbird and cougar site to get the help i needed.


forgot to say i jsut ordered the 3g alt upgrade kit offa some site it came with thew plug for the 3g alternator.

 

[RsStanG1987]

do i need to use the voltage regulator?

 

[KyleEBK]

the 3g alternator is internally regulated so you can jsut ditch the old external regulator that was hooked up.