alternator identification

vagabond80 · #1 January 22nd, 2021, 06:00 PM

I'm finding it hard to get a good specific search with these vehicles, even on simple questions...

anyway, how can I confirm what size alternator is in my '83 signature series TC?
I've seen reference to 2-wire plugs for non-100A

I ordered a belt off rockauto for the 70 - 100 with p/s and a/c, I'm now inclined to believe I may have purchased the wrong one

Thanks
Martin

gadget73 · #2 January 23rd, 2021, 08:20 AM

The 2 plug 65 amp started in 1986. Prior to that they were all a 1g type with one plug and a charge cable that bolted on. They also had an external regulator that would live on the driver's side inner fender area. Honestly thats a good thing, the plug-in connection was prone to melting and catching on fire.

There are two frame sizes, large and small. Large frame was 70 or 100 amp, small frame was somewhere in the 40-60 range. The small frame ones measure 7" mounting hole to mounting hole, the large frame is 8 1/4". Small frame is the most common one, usually the big alternator was on limo prep cars.

vagabond80 · #3 January 26th, 2021, 03:19 PM

Quote:

Originally Posted by gadget73

The 2 plug 65 amp started in 1986. Prior to that they were all a 1g type with one plug and a charge cable that bolted on. They also had an external regulator that would live on the driver's side inner fender area. Honestly thats a good thing, the plug-in connection was prone to melting and catching on fire.

There are two frame sizes, large and small. Large frame was 70 or 100 amp, small frame was somewhere in the 40-60 range. The small frame ones measure 7" mounting hole to mounting hole, the large frame is 8 1/4". Small frame is the most common one, usually the big alternator was on limo prep cars.

you really are awesome gadget, thanks for taking time out of your day to help me and everyone here

TobyU · #4 January 26th, 2021, 05:28 PM

Quote:

Originally Posted by gadget73

The 2 plug 65 amp started in 1986. Prior to that they were all a 1g type with one plug and a charge cable that bolted on. They also had an external regulator that would live on the driver's side inner fender area. Honestly thats a good thing, the plug-in connection was prone to melting and catching on fire.

There are two frame sizes, large and small. Large frame was 70 or 100 amp, small frame was somewhere in the 40-60 range. The small frame ones measure 7" mounting hole to mounting hole, the large frame is 8 1/4". Small frame is the most common one, usually the big alternator was on limo prep cars.

All of my early TCs were limos so I never had seen a small case ford one. LOL When I finally saw one it looked so out of place.
The large case was used on police and ambulances etc too and was the case Lestek, Amptech, Powerline all used for high amp often around 200 or more. Limo builders used them many years past 91 when the 4.6 came along. Some may have still been using them as late as 97. I don't think I have ever seen a 98+ with one not even as a 2nd rear limo alt. They just use two of the 6g factory ones but often the 6g factory in factory location and then a 3g for the rear one until they ran out of their stockpile of them.

gadget73 · #5 January 26th, 2021, 08:53 PM

The idle speed output on those old alternators was fairly dismal. Even the 100 amp at idle was probably only making 25-30 amps. The 60 amp was probably in the 15-20 range. The 3g was better, the 6g is a significant improvement. Apparently there is a basically drop-in option for my Towncar at least should I ever decide to go that route. Might consider it when the current 130 amp dies. I don't need more idle output, but it might make sense for cost reasons to move to a newer one.

The Conti has a 70 amp, the Mark VII has a 100. A 3g would give more idle output, but its working and I'm not real motivated to tinker with it. I have a spare 100 amp that I got new for very cheap on ebay from the Uhaul parts depot. Same unit fits 90s Ford diesel trucks. They were clearing out old stock for 25 bucks a unit, so I bought one. Needs the pulley swapped to use it on either car but thats simple.

vagabond80 · #6 January 27th, 2021, 03:58 AM

Quote:

Originally Posted by gadget73

Apparently there is a basically drop-in option for my Towncar at least should I ever decide to go that route. Might consider it when the current 130 amp dies. I don't need more idle output, but it might make sense for cost reasons to move to a newer one.

What drop-in are you looking at? An upgrade from the meager 60A sounds like a decent idea. Could I assume the factory wiring will be up to the task of the higher output?

gadget73 · #7 January 27th, 2021, 05:37 PM

Mine came with a 65 amp with the fire starter plug, and I dumped it for a 130 amp 3g years ago. There is apparently a 6g that can be used though. Similar total output but better idle speed output. I run underdrive pullies on my car so it wouldn't honestly be the worst thing to consider if and when the 3g dies but until that happens the chances of me messing with it again are pretty low. I honestly don't recall the application, someone I know put one on his 87 Mercury wagon though so I could check with him.

Factory wiring really won' handle much more than stock size. Original 65a 2g harness is a pair of 10awg wires, which comes out close to 8awg. The 1g 100 amp on my Mark VII might be single 8awg and I think the 70 amp on the Conti is the same. The 130 amp on a Taurus uses a 6awg cable. I ran 4awg because I had it. Not sure what the lower amp early style alts used but I doubt very much its fatter than 8awg.

TobyU · #8 January 30th, 2021, 05:36 PM

Quote:

Originally Posted by gadget73

The idle speed output on those old alternators was fairly dismal. Even the 100 amp at idle was probably only making 25-30 amps. The 60 amp was probably in the 15-20 range. The 3g was better, the 6g is a significant improvement. Apparently there is a basically drop-in option for my Towncar at least should I ever decide to go that route. Might consider it when the current 130 amp dies. I don't need more idle output, but it might make sense for cost reasons to move to a newer one.

The Conti has a 70 amp, the Mark VII has a 100. A 3g would give more idle output, but its working and I'm not real motivated to tinker with it. I have a spare 100 amp that I got new for very cheap on ebay from the Uhaul parts depot. Same unit fits 90s Ford diesel trucks. They were clearing out old stock for 25 bucks a unit, so I bought one. Needs the pulley swapped to use it on either car but thats simple.

YES! That is why most Amptech, Lestek, Powerline models had a smaller pulley to speed up rpms at idle.
We had several limos that would discharge at idle with everything in back on (this was in the day or one alternator limos) because they had factory size pulley.

TobyU · #9 January 30th, 2021, 05:38 PM

I had my 1990 truck with firestarter catch fire one day. Was almost to my mom's house when it started bucking.
I pulled in and saw smoke. Ran and grabbed water to put it out. My next though was to pee on it.

Only damaged the harness right at alt. New alt and harness that came with it and good to go.

gadget73 · #10 January 30th, 2021, 08:30 PM

even with a smaller pulley there is only so much you can get from them. The stock pullies were usually not that huge so there is only so much smaller it can get and still fit the shaft and get decent belt wrap.

I have the slightly smaller 2g pulley on my 3g to compensate for the underdrive crank pulley. When I had an electric fan it caused me a lot of trouble. The fan is gone but I have no real reason to change the pulley back. That and I don't have it here anyway.

TobyU · #11 January 30th, 2021, 09:03 PM

Quote:

Originally Posted by gadget73

even with a smaller pulley there is only so much you can get from them. The stock pullies were usually not that huge so there is only so much smaller it can get and still fit the shaft and get decent belt wrap.

I have the slightly smaller 2g pulley on my 3g to compensate for the underdrive crank pulley. When I had an electric fan it caused me a lot of trouble. The fan is gone but I have no real reason to change the pulley back. That and I don't have it here anyway.

They had it all figured out and was only a little smaller but I thinkit gave at least 200 RPM higher rotor speed.

I know we had at least two limos that would discharge only at night with headlights on and in summer with front ac and rear ac blowing on high and only in drive.
If you simply turned the front blower to down one notch to med high it would no longer be discharging and would hold steady.
I got good at this and would turn my front blower down a notch or two if I heard the radio start to cut out. Otherwise I would have to put it in N in traffic.

So it was very close to being just enough to maintain charge.

The smaller pulley was jsut enough to make it ok in worst of conditions.
The stock belt still worked too as the tensioner was able to take up the slack with no problems.

Did this on an Ultra 14 pass 1996 or 97 car and a Turtle Top limo bus with V10.
Most limos after 98 went with 2 alts. Even the little 60 inch 6 pass ones that could have easily been fine with one.
They just standardized everything under the hood since they were all the same up front.

I do have one now though with a 6g for the front and a 3g for the back.

I prefer the same parts so I can swap things if need be.

That's why at any one time in my family we have 6-7 ford alternators under the hoods.