• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Alternator wiring 5.0 swap

stevencsat

New member
Joined
Jan 19, 2017
Location
Houston, TX
Hey guys,

For anyone that has done the 5.0 swap in their Volvos, how did you wire the alternator? All the stuff I found online talks about tying into the factory harness, but I replaced mine with the Painless harness and it doesn't have any wiring for the alternator. Any ideas or anyone have a picture of how to wire it up?
 
yelp, easy do a one wire alternator to the battery. Not unless you have your alternator already. How the 5.0 in the volvo does it handle the extra weight and power well?
 
Well I actually just got the project not too long ago. I have the car running and just got the clutch cable sorted out last night but haven’t really been able to drive it yet. Everything I was reading was saying the one wire setup was on a 3g alternator swap, will it work on the stock 88 mustang alternator?

Mogly, I’ve searched a ton and like I said everything has been showing how to splice an alternator into the existing factory harness. Maybe I just missed it in my searches but I haven’t come up with anything from Google
 
Scratch that, I figured I’d just buy a one wire high amp alternator to get rid of this crappy stock one anyways. Thanks guys!
 
Do you have the old harness leftover? It may have the alternator harness/wires incorporated depending on the year (my 95 was partially in with the injector harness. Having that will help. If not there are vendors that make a retrofit harness for the mustang alternator that may aid as well. Like Mogley said above, your main concern is to find which is the exciter wire from your alternator harness to hook to the Volvo harness for power with key on and key run. I believe I wrote some notes on my wiring diagram. I can check this evening if needed.

Edit: correct me if I am wrong, but doesn't the 1 wire alternator place a drain on the battery when not running since it always stay "excited"?
 
PeaceEngineered, I tossed the factory Mustang harness because the PO hacked and spliced in ways that weren't even safe to look at. He didn't even have the alternator wired when I got the car, so I think the alternator harness and wiring were missing to be honest.

I'm not too sure on the one wire alternator draining the battery, but I have seen several people in the Mustang forums and other discussion boards who run them with no major issues. If it becomes a problem, I suppose I could just wire in a switched relay or a toggle switch as a last resort
 
There's typically 2 different types of alternators used on ford 5.0, 2G (more common in the era) and 3G. Both were used, both have different wiring diagrams. External voltage regulator?
A picture is all it would take to identify the alternator. These are incredibly easy to wire up.
 
It's definitely a 2G alternator, which I believe was supposed to have an external regulator. The motor is all stock from a 1988 Mustang GT, minus the MAF and injectors I added
 
I think the difference is external fan (2G) and internal fan(s) on the 3G as for a tell between the two physically. I do believe both are internally regulated- 3G for sure as it is wired in my car. I have to agree that these are simple connections that could save you some bucks. Also, alternators are known to go bad at the least opportune moment, it would nice that if that happened you could easily get a replacement at any parts house.
 
Back
Top