My 5.9's alternator decided to die on me last nite and since the 150 amp it uses are in short supply, i.e. non existent, and all the replacement alternators are 134amp which is a downgrade I decided to swap the 160amp from a 2003 Dodge Durango into my rig. Wicked over on thespeedfreaks.net gets credit for the original write up and for being the guinea pig who first tested it. **Usual disclaimers** I am in NO WAY responsible for any bad stuff that happens to you or your rig by attempting this swap! If you set it on fire, fry your PCM, burn your finger soldering wires, etc, its all on you! Now on to the fun stuff!
1) 2001-2003 Dodge Durango 160amp alternator w/ connector and pigtail of wire approx 4-8" long. Alternator P/N# Denso 56029 915AA
2) Soldering iron and good flux core solder
3) Propane torch
4) 1/8" heat shrink tubing
5) electrical tape
6) (1) 3/8", 6g ring connector / (1) 7/16" 8g ring connector <--these are what I used but depending on where you ground it these sizes may vary!
If you have a Haines/Chiltons/FSM or even super basic mechanical skill you can skip the boring stuff below and move on to the wiring part of this post.
1) Remove negative battery cable from battery
2) Remove upper and lower alternator mounting bolts and pull alternator out far enough to reach connectors on the backside or you can remove them while its still bolted to the mounts, your choice but its easier with the alternator removed and laying face down
3) Remove nut holding red (+) wire from the back of the alternator
4) Remove nuts holding the black box/connector from the back of your stock alternator
5) Remove old alternator from your vehicle and set it aside
6) Install new alternator into vehicle, minus the wiring
First of all is the alternator and its required wiring pigtail. I picked mine up from a local wrecking yard out of an 03 Durango 5.9 with low miles and w/ pigtail for $40, a steal compared to the $160 for a decent rebuilt 134 amp alt!
Once you have the new/used alternator bolted back in place its time to start on the wiring. First of all the black box/connector/ground thing needs to be removed so chop it where I've shown in the picture;
Once you cut the black box off the end your going to be left with 4 wires to deal with. First is the 2 green wires for the "Generator Field Driver" and "Generator Field Source", these 2 wires will go to the pigtail/plug that connects to the back of the new alternator. Second is the large black wire which is simply a ground strap. Lastly is the red power feed from the alternator to the PDC, Starter and Battery. At this point you can cut the end off the red wire since it needs to be replaced with a larger one.
The solid green and green/purple striped wires from your stock harness (colors may vary yr to yr/model to model, check your FSM) connect from the PCM's "Generator Field Driver" (solid green) and "Generator Field Source" (green/violet) to the original alternator plug. Wicked's write up points out that these wires can apparently be switched with no ill effects but I chose to match them to their respective spots on the PCM. On the Durango the colors are different being I had 1 solid green wire and 1 white with black stripe wire. The solid green wires both correspond to the "Generator Field Driver" on each PCM so thats how I wired mine up. Start by stripping the ends of the 2 solid green wires, 1 from your harness and 1 from the new pigtail and twist them together. Repeat this process for the green/violet and white/black wires as shown below. be sure to slide a piece of heat shrink tubing down each wire prior to soldering, then solder the wires avoiding a cold solder joint. Once the solder joints cool apply the heat shrink tubing and wrap the wires together with electrical tape.
Next up is the heavy black ground from the black box you cut off and the red power feed that attaches to the alternator. This cut ground needs to be connected somewhere to a ground point and you can see in the picture below theres a few to choose from. I picked the factory ground point behind the tensioner where the green arrow points. This is where I used the 8g 7/16" ring connector. You could choose to just crimp this and the red power feed from the alternator but I chose to use solder, hence the need for the propane torch. To solder joint the rings to the wires simply strip 1/4" of insulation off the cut end, insert into the ring connector then heat the the very end of the ring connector until the center strands of wire get hot enough to melt the solder. Keep applying solder to the strands until the joint is full and completely soldered, repeat this process for the red wire. Once they cool down, wrap the red wire end with electrical tape or heat shrink then bolt the ground to your choice of places on the engine and the red power feed to the back of the alternator.
Ground wire and ground points;
Power wire with soldered on 3/8" 6g ring connector
Finally, plug the connector into the alternator, double check all your wires, bolts/nuts, reconnect the negative battery cable and fire her up! I'm not exactly sure how long my alternator had been going out for but I noticed right away all my lights are brighter, there's no noticeable drop in my dash lights when the e-fan kicks on and having everything (heater/stereo/lights/wipers) on doesn't make my voltage gauge drop or my lights dim out.