1G Alternator "F" Terminal?

Topic: 1G Alternator "F" Terminal? (Read 3454 times) previous topic - next topic

1G Alternator "F" Terminal?

May 23, 2015, 09:48:36 PM

Switching out the 1G alternator and I am pretty sure I have the wiring down except for this "F" terminal. I have checked replacing the 1G with the 2G and 3G and cannot find any information on what to connect the "F" terminal to on any update. Below is a specs I found and a photo of my regulator connector showing the available wiring. Strangely the manual says "I" terminal is Green & Red stripe, but mine looks White with a red stripe. I suppose Ford ran out of the Green and red wire that day and used White and red, lol. I seem to see this wiring issue pretty commonly also. So, I guess it is a guessing game at times if the guide manuals are incorrect.
Anyway, Is this "F" terminal used and where should it be wired into on either the 2G or 3G?

Here is the 1G,2G and 3G I located. The spec seems to show the F terminal as black, and again my photo shows a different color wire for F.

1G Alternator "F" Terminal?

Reply #1 – May 23, 2015, 10:20:49 PM

AFAIK there is no connection used on the F as that connection is internal on a 2G/3G...

Check out page 20 & 20A for actual Ford wiring...

https://plus.google.com/photos/116504312330534460153/albums/5791467123979845937/5791467604974452754?banner=pwa&authkey=CMuUiNWbkfzJiQE&pid=5791467604974452754&oid=116504312330534460153

1G Alternator "F" Terminal?

Reply #2 – May 23, 2015, 11:38:21 PM

Thank You for that and the manual, always nice to have those also. Mine is the 5.0 but I imagine the 3.8 has the same connections. Looks like 20A is for mine.

1G Alternator "F" Terminal?

Reply #3 – May 24, 2015, 02:33:19 AM

Unless i am reading it wrong,its for the external regulator,which is built in on a 3g.

If your doing a 3g upgrade, make sure you have a sufficient fuse and run a new power cable to the starter solinoid. No reason to mess with two small 30 year old power wires when your talking about the power levels we have here.

The stock ford 3g wiring used a 175 amp fuse and 8 gauge wiring from what i saw. This is right on the edge of the maximum handling capacity of an 8 gauge wire at less then 10ft of distance. Mine ended up being around 7 feet long, so i used 6 gauge cable. Don't forget to check/ upgrade your block ground as well.

Let us know if you have any more questions. Those 175 amp fuses are about 5 bucks a piece. I picked up a couple at the junk yard for spares.

1G Alternator "F" Terminal?

Reply #4 – May 24, 2015, 04:11:19 AM

Why would you need 10feet of battery cables? Did you relocate the battery in your trunk?
I have already updated my ground wire from the battery negative to the block and frame with heavy gauge and added negative cable from the motor to the vehicle. From what I have been seeing, there have been some issues with the electrical on ford cars in the 80's.

Especially the connectors on the 2G alternator which have even started fires around them. I am taking every precaution with this part of my build by installing new and larger (lower gauge) wire as required by the F/CMVSS. I also will probably install a battery disconnect switch with the new high amp fuse.

The 3G alternator from what I have read is called an internal regulator, though I can understand what you said about it being external since it rides on the alternator. I just want to remove this garbage 1G ran regulator that came with the car since it is probably 30+ years old and well over due for an upgrade, as well as the alternator.

I did some amp ratings with what this build will have and it is going to be in the range totaling just under 100amps. I'm sure a 130 amp alternator will be plenty. If I can find a quality built alternator without getting ripped off with inferior internal parts, I will go higher.
I will not be doing any type of heavy welding through my alternator or pushing a high amp boom box radio or pushing hi-amp headlights with the car. I am running the MSD box and blaster coil, with AC and the other factor installed accessories. I will also have relays for anything I add extra and duel relays if I replace the clutch fan with an electrical temp controlled version.

But anyway, back to my original question. I wanted to be sure that I don't miss anything with the upgrade to a higher amp alternator and so far things are going well, I just get confused when reading specs on the 2G and 3G and they did not show the "F" terminal connection from the 1G being used on the upgrades. Electrical is not my most favorite thing to work on and I probably make it harder on myself then it actually is, but safer is better then a possible melt down with family in the car.
If you know of a location that possibly has an affordable 3G alternator and install kit, I would appreciate the info since I am in the market for a new one.

This is a PDF file which gives the Ford Electric Requirements as stated for the F/CMVSS and Canadian RFI Requirements:
Instructions for the addition of electrical devices to the vehicle electrical system by body builders.

PS. TurboCoupe50, both those cars you have look just beautiful. Really like that Fairlane Cobra. I had a friend that had the Cylcone version of that car in almost the same condition too.

1G Alternator "F" Terminal?

Reply #5 – May 24, 2015, 09:59:54 AM

Quote from: BradMph;448276

Thank You for that and the manual, always nice to have those also. Mine is the 5.0 but I imagine the 3.8 has the same connections. Looks like 20A is for mine.

Yeah I chose that diagram as the '86 3.8 still used a 1G, easy to compare differences... I used those same diagrams, plus a '72 diagram when I was rewiring the Comet for a late alt...

For the 10ft wire mentioned, Stack is saying that's a maximum length to carry 175A without increasing wire size... Taking routing into consideration, you'd need more like 18-20 ft if battery were in trunk... BUT one should never run a charge wire that far, wiring it to the battery cable(that should be 0 or 00 cable) at solenoid is a far better solution...

1G Alternator "F" Terminal?

Reply #6 – May 24, 2015, 07:52:24 PM

I ran my cable from the alt to the headlights harness, over through and around the radiator support, but a fuse near Tue battery, and a 18" piece of wire from the fuse to the battery. Mine was actually over 8ft in length, but i was also adding an electric fan and decided that was the shortest way to run the wiring and to do it all together and at once. Plus the cable i used was the same price if it was 48" in length or 72", as well as rated for the load at that length.

Most stock 3g alts put out over 90 amps at idle and around 160amps 2000rpm's and up, that is why a ford taurus, mustang and anything else with a 3g (including the 95amp 3g's) use a fuse and cable rated for 175 amps.

If you don't think your car stock, only factory options doesn't use more then 60 amps, ill bet its really close.

A 1156 light uses 12w at 12volts, or one amp (since watts=voltage x amps) when your car is running, voltage should be between 13.5-14.2 volts. Anything under 12.6 is actually discharging the battery. My 86 has 12 lights on the back of the car, counting brake and marker lights. There are 2 filaments in a 1157 bulb, meaning it probably takes twice the power. So just rear tailights we might be using anywhere from 12-24 amps, and that is only assuming that we hit the brakes with the marker lights on. Then you have 55w headlamps, or 105 watts total, plus another 6 front marker/turn signals, so lets just call it 12 amps for the rear lights, 6 amps for the front, and 10.5 for headlights. So we have 28.5 amps, minimum just for turning on out head lights, with up to 40 amps when we hit the brakes. We haven't gotten around to interior illumination (i think my stock base cluster has 12 or 15 light bulbs), load used by the engine, comfort items (power seats, windows, mirrors etc) let alone an after market stereo.

Wiring is way, way undersized on these cars, even stock. The only saving grace is that it uses most items on the car intermittently. When i pulled the old wiring off of my stock 2g alt, the wiring connectors and wires crumbled in my hand and were charred black. Yet, the stock 2g alt only puts out 25-30amps at idle and 50-60 amps at full tilt, which is well within the range of my single 10gauge cable, let alone two of them, like the stock 2g cable uses.

Am i over explaining, and maybe even slightly over exaggerating some numbers? Maybe.

Your 130 amp alt is going to be capable of using over 160 amps. 1 hp= about 736 watts. Again watts=amps x voltage. So 130 amps times 14.2 makes 1842 watts. Ever see how big the wiring is on a 1850 watt amplifier? 2.5 hp, just in the alt itself, or almost a hair dryers worth of power

1G Alternator "F" Terminal?

Reply #7 – May 25, 2015, 02:42:02 PM

Quote from: Haystack;448284

Am i over explaining, and maybe even slightly over exaggerating some numbers? Maybe.

Applying for a bar exam anytime soon???:rollin:

(just messn' wich ya), good post...

1G Alternator "F" Terminal?

Reply #8 – May 25, 2015, 06:20:58 PM

How'd ya pass the Louisiana state bar? Ill tell ya for half that eclair.

1G Alternator "F" Terminal?

Reply #9 – May 26, 2015, 12:13:57 AM

LOL you guys are hilarious. :p:

Ok after reading everything I could on this upgrade and seeing twice as many specs on the subject, this is what I think it will require.

The '85 TBird uses a 4 pr0ng regulator ( I,S,A,F) plug in. I used a flat connector placed onto the green/red wire on the 3 wire plug (ASI) on the new 3G and plugged it back into the green/red wire connector on the old regulator plug to maintain that connection. I then secured the connection and taped up the regulator plug with that single green/red connected.

Next I took the white/black wire from the 3G 3 wire connector and placed a single female connector on the end and plugged that back into the 3G rectifier single male connector at the 12 o'clock position on alternator completing that connection.

The final 3rd wire on the 3 wire 3G connector is the Yellow/white signal wire. I connected this last wire to the main power connection at the + terminal of the 3G alternator.

Attached a ground to alternator case that also went to frame and block, then negative battery.

I also spliced into the White/Black wire at alternator with the red kit wire for the Edelbrock carb elec.choke and grounded the choke with the kit black wire.

It's like a mad scramble to make a deadline to post in this forum, otherwise it logs you out. One word for this is..."SuCkS"

1G Alternator "F" Terminal?

Reply #10 – May 26, 2015, 12:31:15 AM

I hope that's a AGM battery, otherwise the electrolyte is gonna short out your alt...:hick:

Seriously, looks like you have it...

Now it's time to upgrade to a PMGR starter...