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I have a '86 f150 4.9 carb. W/ac 4 speed manuel.
last week the choke wire fell off and grounded, melting down it and the smaller 12ga. Green wire from my alternator. Can someone help me determine where to attach a new 12ga green wire too. It's all but disappeared...I can't find what it was attached to.
I'm not sure. Tomorrow I will try and remove it and take some pictures. Thnx for the reply. I don't yet know how to use this forum, recieve notifications, etc..once I do, I can respond quicker.
For the next step you will need to pick up on of these at the auto parts store.
Ford 2G 3G 4G Alternator Harness Voltage Regulator Connector plug 3 Wire Pigtail https://us.amazon.com/Alternator-Har.../dp/B014GIVMJO
For the next step you will need to pick up on of these at the auto parts store. Ford 2G 3G 4G Altern
Thank you sir...I will do that...but one more question. Do you think I should replace the regulator also, or upgrade to a 3G. My truck still runs, charges fine. About 4 years ago the original alternator went out on me. I went to a O'Reilly parts house here and got one they said I would have to solder the wires into my harness...crazy I thought, but okay...it is antique. That went out about a year later. I went back to the store and got a replacement under warranty that was fitted to accept the original equipment connectors. Good thing I just soldiered the other alternator wires "T'D" into my original wiring. So all I had to do was cut the soldered "T" wiring off and use my original connectors...a year later that alternator went out. I went back to the same store for another Warranty and they tried to replace it with another soldered wired alternator. I refused that one and made them refund my $. I went to Ford and ordered a alternator from them...this one lasted maybe 1 1/2 years now...so far. Do you think it may have got damaged any from my choke wire melt down..should I replace it or upgrade to the 3G...I was reading how this 2G can be a fire hazard at the connectors
My recommendations to change out the voltage regulator (VR) plug was based on it being the original 2 wire style shown in post 2 and also that you said the green wire was not connected to the VR plug anymore.
But if you have already upgraded the VR plug and it is in good shape don't just run out and buy another one. If your ALT works now, it still has the green wire attached to the VR plug as it wont work without this input.
If you want to change to a 3G ALT it's really a personal choice. Are you running extra loads or just the stock stuff that came with the truck?
I will let others jump in here to share there 2G to 3G swap experiences. For me I would would never recommend a 2G ALT. The 1G is fine, I would have just run a 1G if that is what my truck came with, but all my loads are still stock.
You can run a GM alternator also. I would run anything but the 2G you have. The reason you are having to mess with the wiring is because of the connector problems associated with that alternator.
To follow up on your comment about the fire hazard at the connector issues... here are some photos. First a 2G rectifier and matching power plug.
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Note that all 6 diodes are in a small area, about 2.5 inches across, thus all the heat has to be dissipated in the same small area. More on the heat produced by diodes later.
The power output, say 60 amps, is split between two push on wire connectors. A nut on a stud is a much better power output connector.
Now take a look at a G1 rectifier...
Note the spacing on each diode. The heat is spread across a larger area, 3 diodes on each side.
Alternators are 3 phase, so in a 60 amp ALT each phase produces 20 amps. Each phase has 2 diodes. Each diode has a .7 volt drop across it. Each diode produces 28.57 watt of heat at max output of 60 amps. All 6 = 171 watts at max output, but even at 30 amps output the heat generated is still around 85 watts. If the push on power out connector is weak and not making a good connection (high resistance) this will add more heat. More heat causes more resistance... aka a "death spiral".
As you have learned, even bypassing the original push-on connector, the heat dissipation problem from all 6 diodes in such a small space cant be fixed.
I will let others jump in here to share there 2G to 3G swap experiences. For me I would would never recommend a 2G ALT. The 1G is fine, I would have just run a 1G if that is what my truck came with, but all my loads are still stock.
Jim
I have an 82 F100 4.9 that I've been fixing up. My truck has just over 43k miles on it, and I use it as a daily driver. I also have a matching camper and once I get the truck ready I plan on driving it cross country. Which is exactly why I chose to upgrade to a 3G. If i'm 4 states away from home and it goes out - a person can easily find 3G alternators at about any parts store, whereas my original would probably have to be ordered and i'd be stranded for at least a couple days. (I'm using the model alternator that came out of 1990's taurus v6's) Plus I'll be running extra load with the camper and stuff. For me and my lack of experience, the 3G upgrade was weeks of research and about 2 hours of actual work (cuz i'm old and slow) Its pretty straight forward. I had already done a conversion from alt meter to volt meter in my instrument panel, that is a time consuming aspect to consider as well. There are lots of posts about the upgrade, all said and done I'm extremely happy with it and glad I did it.
When doing the conversion, 3G alternators have regulators built in - so that part gets removed from the truck. I used that physical location to mount a circuit breaker from alternator (personal preference, I did that in place of a consumable fuse). More than happy to share more specifics if anyone is interested in hearing about it.
