PT1850 Alternator Conversion

[Bob999]

I didn't realize it had any fuses until I saw the wiring diagram, I'll have to track 'em down.

I believe the 1845 and 1850 are identical from an electrical standpoint. There is a 20 circuit breaker located on the dash board. The fuses, a 20A and 50A, are located on the outside of the engine compartment junction box located on the right? (side opposite the oil fill/dipstick) side near the rear.

 

[AltavistaLawn]

I believe the 1845 and 1850 are identical from an electrical standpoint. There is a 20 circuit breaker located on the dash board. The fuses, a 20A and 50A, are located on the outside of the engine compartment junction box located on the right? (side opposite the oil fill/dipstick) side near the rear.

A big double Kudos to you and Sedgewood for those wiring diaphrams. I had a number of problems.

1. We didn't track down the correct fact. wires for the alternator, some how when testing the factory wire didn't light. Prob., test light ground? We ran a new wire to the "on" from the switch, which rubbed thru and shorted.

2. I found a loose wire in th dash, where I added. Tyring to rerun it and clean it up; I switched the hot that was supposed to power on the Fuel shut off solenoid.

3. I was looking at te wrong thing, thining it was the FS; te FS wasn't clicking on whe I thought it was. Terry at PT straightened me out on that one.

4. I unhooked the jucntion box to try to get to those fuses, when unhooked it doesn't ground, and the FS wouldn't work.


All the problems were fixed by 1:00 today. The alternator is working perfectly, and now it cuts off by the key.

 

[Charlie_Iliff]

A big double Kudos to you and Sedgewood for those wiring diaphrams. I had a number of problems.

1. We didn't track down the correct fact. wires for the alternator, some how when testing the factory wire didn't light. Prob., test light ground? We ran a new wire to the "on" from the switch, which rubbed thru and shorted.

2. I found a loose wire in th dash, where I added. Tyring to rerun it and clean it up; I switched the hot that was supposed to power on the Fuel shut off solenoid.

3. I was looking at te wrong thing, thining it was the FS; te FS wasn't clicking on whe I thought it was. Terry at PT straightened me out on that one.

4. I unhooked the jucntion box to try to get to those fuses, when unhooked it doesn't ground, and the FS wouldn't work.


All the problems were fixed by 1:00 today. The alternator is working perfectly, and now it cuts off by the key.

You're having altogether too much fun.

 

[AltavistaLawn]

I finally got around to modifying the hood to accomodate it. The side hood swings to the rear for access to the oil, and alternator. Just a little more and its finished. Don't look too close, I let it get out of square before final welding it.

 

[AltavistaLawn]

Notice the two pieces of 2 angle on the rear, I needed more room for the hinges, and they are the beginning of the rear air induction system, I'll be fabricating soon.

 

[ponytug]

I think JJ's right, and it is a function of the single wire alternator. As I understand it, the initial field voltage to the alternator before starting is supplied by the "ignition" post of the starter switch. Once running, the regulator keeps that field voltage at its set level, no longer needing the battery connection. (Do we have an alternator guru lurking?)
A kill switch in the fuel solenoid line solves the problem. It may also work to wire it to the accessory circuit rather than the ignition circuit. The accessory circuit should still shut down when the key is turned off.

Charlie is right on the theory of one wire alternators. I have never really wanted to put it to the test. They do have the advantage that they are easier to wire.

The downside is that they measure the voltage at the alternator and project that voltage back to the rest of the tractor. So... If you don't have a heavy gauge wire connected to the alternator/battery/main fuse, the battery may not be getting all of the voltage it needs to fully charge. You also need to make sure that the electrical path between the alternator and the battery stays clean and free of oxidation. A little antioxidant paste will go a long way. (It is a good idea generally, but critical there.)

West Marine has a nice chart of wire gauge versus load. I tend to use the 3% chart for loads like lights, since it lowers the energy losses. Don't forget to count the ground length in the total number of feet. I added a couple of extra ground wires to my old pickup, all tied to a central point, which really helped the electrical system run better. ('88 diesel, 380k miles.)

All the best,

Peter