3g alt upgrade and electric fan.

January 26, 2015, 11:20:54 PM

This was super easy to do if you follow the wiring diagrams in the greatest hits. I did see one part i have a question on.

It says the headlights are wired into the old power wire. I didn't reconnect the old wire and left every thing on the solenoid as is, except for the new cable. Is there a benefit to doing this? I didn't have any 10 gauge wire on hand, so i just skipped it.

My thinking is that the headlights will still feed power from the splice point with the old wire taped up. The fuseable link should still protect the wire in the case of a short, so i see no benefit to this unless i need to go through the harness or add headlights relays later.

Just a quick parts list, in case anyone is searching for info.

I used the harness from a 93-94 tbird with a 3.8 for connectors to the alt, but the stock tarus one works fine. I just damaged a connector trying to get the first one off. Then i unraveled the tape and removed the 8 gauge factory wire. I replaced it with a 72" long 6 gauge starter wire(6 gauge wire with lugs on both ends).

I connected the other end to a mega fuse holder i picked up from napa. I tightened the stud down over a 175amp mega fuse off of the side of the 3g donors fuse box. I then connected the other end with another 12" 6 gauge starter cable from the fuse to the solenoid.

You really only need to throw a lug on the yellow wire back to the main output stud and splice the green wire from your factory harness. Everything else is plug and play off of your new harness.

$13.99 for the alt.
$10 for the mega fuse holder.
$2.99 for the alt pigtail.
$11.99 for the 72" cable.
$5.99 for the 12" cable.

Couple of misc connectors and they threw the fuses at me for free.

I used the ford 175 amp fuse for a few reasons.
the alt makes 60-90 amps at idle, and 160 amps at 2000 rpm's.
The circuit breaker i wanted was $35
Every 3g equipped ford from 94 on uses the same fuse. Mustangs, taurus, crownvics ect.
a new 175 amp fuse is available for $4.99 at my local parts store.
And the 6 gauge wire i used should be good for 300amps with up to 10 feet of cable. I had 7' in total, plus the mega fuse holder.

3g alt upgrade and electric fan.

Reply #1 – January 26, 2015, 11:22:13 PM

Oops, 200 amps. Also forgot the $1 for the 3/8" 2" long bolt, nut and two washers.