3G Alt Swap
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
3G Alt Swap
Hey everybody,
I got a great deal on a 3G alt the other day for $35. Had it tested and it works great but it's a little dirty though. I'm gonna clean it up and install it in my '84 250 diesel. I'm making the battery charge wire out of 1ga cable and a 150amp mega fuse. I ordered the fuse and holder today. I gotta get the alt harness from fordfuelinjection.com still. I'm just wondering, in that harness, the yellow wire out of the big plug goes to the bat post, the white wire goes to the single plug on the alt, and the third wire out of the harness goes?????? My truck has the 1G alt with the external VR. I also have the amp gauge on the dash. Do I send any wires to the VR or can I scrap it since the 3G has the VR built in. I'm planning on installing aftermarket gauges so i'm not worried about the stock gauge working. How would I wire up the aftermarket amp meter? Wire it to the starter solinoid?? I'm really excited to get this alt installed. I hope to have it in this weekend!!! Thanks guys.
I got a great deal on a 3G alt the other day for $35. Had it tested and it works great but it's a little dirty though. I'm gonna clean it up and install it in my '84 250 diesel. I'm making the battery charge wire out of 1ga cable and a 150amp mega fuse. I ordered the fuse and holder today. I gotta get the alt harness from fordfuelinjection.com still. I'm just wondering, in that harness, the yellow wire out of the big plug goes to the bat post, the white wire goes to the single plug on the alt, and the third wire out of the harness goes?????? My truck has the 1G alt with the external VR. I also have the amp gauge on the dash. Do I send any wires to the VR or can I scrap it since the 3G has the VR built in. I'm planning on installing aftermarket gauges so i'm not worried about the stock gauge working. How would I wire up the aftermarket amp meter? Wire it to the starter solinoid?? I'm really excited to get this alt installed. I hope to have it in this weekend!!! Thanks guys.
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
Well I may have found my answer. The last wire goes to a hot in run wire. Isn't there one off the old VR I can send it to so my gauge will work in the meantime?? Seems like thats what I should do. I remember when I rewired my alternator last summer, I lost operation at the gauge. Must have done something wrong. I'll find the right wire and fix that too.
Postmaster
Joined: Apr 2008
Posts: 4,802
Likes: 1
You remove the old VR entirely. There is a single green/red wire coming from the truck's body harness to the VR, it's a key-on wire and it triggers the VR and therefore the alternator. What you do when you install a 3G is you cut this green/red wire off the VR plug and extend it and splice it into the green/red wire coming of of the 3G's plug - this is now your 3G trigger wire, it actually works the exact same way it did before only since the 3G VR is built in the alt there are no extra bulky harnesses between them. If you have a black ground wire between the old VR and the fender sheetmetal, remove that as it is no longer needed. In reality you rip everything out, old VR and alt and the harness between them, the only thing you're left with before you drop the 3G in is the green/red trigger wire for the old VR, and maybe a charge cable if you already had a nice and big one.
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
I didn't have a big charge cable before so i'm making one out of 1ga cable with a mega fuse between the alt and the battery. Is it best to hook this cable directly to the battery or to the solenoid?? I think i'm gonna put it right to the battery. I'm sure this is a dumb question but running the bat cable to one battery will charge both batteries correct??
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
Awesome, I ordered the harness today so i should be golden once that gets here!! Can't wait. I'm like a kid in a candy shop with this stuff. I'm also starting to like NAPA more and more because they just always seem to have EVERYTHING and if they don't they can get it. I just with they came and installed the stuff!! I guess I enjoy doing stuff like this because it adds to the truck but I don't like repairing stuff when it breaks.....
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
Trending Topics
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Postmaster
Joined: Apr 2008
Posts: 4,802
Likes: 1
Well that depends, where are your largest power draws from? For instance I have over 1kW of lights on my truck, and they all pull directly from the batteries. I also have a power inverter that pulls from the batteries. I added a big power cable for the glowplugs relay (factory stuff is scary tiny for the current that flows through there), and that pulls straight from the batteries too. So see, for me it made perfect sense to hook up the charge cable directly to the batteries, this way the short cable between the passenger-side battery and the starter relay on the fender don't bottleneck my system (even tho I've upgraded that one too). On the other hand, if most of your electrical loads are hooked up to the starter relay, then it would probably be a good idea to hook up the alternator cable there as well, again to avoid the short cable bottlenecking your system (only in the opposite direction from mine). I'd suggest you upgrade that short cable anyways, regardless of where you hook up the alt charge cable...
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
I'm gonna do that too. I'll have plenty of 1ga cable left to make a jumper from the battery to the solenoid. That way all my bridges are crossed with good stuff. While i'm at it, i'm gonna upgrade the wire going to the starter from the solenoid too. There's just small stuff on that too. I know all the wire does is send the signal from the top solenoid down to the solenoid on the starter but I might as well upgrade it since i'm doing everything else.
Tuned
Joined: Nov 2002
Posts: 348
Likes: 0
From: Benson, AZ
Just a few questions
1) Can the Yellow/white wire be hooked direct to the charge wire to eliminate another wire going to the fender?
2) Isn't the Chassis ground the case of the alt? If not then wouldn't you need an equivalent negative wire to go to the battery?
3) What years were the 3G alts used if they ask for an application?
1) Can the Yellow/white wire be hooked direct to the charge wire to eliminate another wire going to the fender?
2) Isn't the Chassis ground the case of the alt? If not then wouldn't you need an equivalent negative wire to go to the battery?
3) What years were the 3G alts used if they ask for an application?
Last edited by macman85602; Mar 23, 2010 at 05:52 PM. Reason: Clarity
Postmaster
Joined: Apr 2008
Posts: 4,802
Likes: 1
Just a few questions
1) Can the Yellow/white wire be hooked direct to the charge wire to eliminate another wire going to the fender?
2) Isn't the Chassis ground the case of the alt? If not then wouldn't you need an equivalent negative wire to go to the battery?
3) What years were the 3G alts used if they ask for an application?
1) Can the Yellow/white wire be hooked direct to the charge wire to eliminate another wire going to the fender?
2) Isn't the Chassis ground the case of the alt? If not then wouldn't you need an equivalent negative wire to go to the battery?
3) What years were the 3G alts used if they ask for an application?
2) Yes, alternator ground is through its case. You still need a nice ground cable between the batteries and the engine, and between the frame and the engine.
3) '92-'94 Taurus 3.8 V6.
Thread Starter
|
Senior User
Joined: Oct 2007
Posts: 256
Likes: 0
From: Good old Oswego.
UPS delivered my harness today so guess what i'm doing tomorrow?!!?!?!?!?! You guessed it, I will be converting alternators. It should go pretty easy and quick. I'm gonna grab a new belt too. If only these trucks used serentine belts!!! I'll let everyone know how I make out......maybe pictures too?!?!?!