1973 MF 150 Perkins Diesel

[Inolaway]

I have a MF150 and have spent the last year restoring it. I am at the point of rewiring it. The current system used a positive ground, with single wire alternator. Can this be changed to negative ground by just switching the cables? In other words red to the starter and black to the frame? Is it 6 of one and half a dozen of another? Does the single wire alternator put out positive or negative or does that matter?
How do I make sure the battery is trickle charged as the alternator is spinning?
It had a regulator on it because all the old wiring to it is still there. Is all that old wiring unnecessary with the one wire alternator?
As I understand the single wire alternator eliminates the need for the inverter and regulator as that is housed in the alternator. If I run the single wire from the alternator to the ammeter or the "L" side then where does the "B" side wires need to go?
Also I have two 1/4 inch spade connectors on the back of the oil pressure sensor, I read where you should break your wires between the two connectors to have your gauges electrified and the alternator excited when the engine oil pressure comes up as it is running because the sensor acts like a light switch. What two wires do they need to be?
Thank you!

 

[Kenneth S]

Never heard of a 150 in the U.S. with a positive ground system, but if it is to change it you have to reverse the polarity of the voltage regulator, or just replace it with a negative ground voltage regulator (the single wire alternator does not eliminate a voltage regulator it just replaces an external regulator). On the amp meter the wires get reversed, and the old wiring to external voltage regulator, and the regulator can be removed.

Here's a wiring diagram.

 

[Inolaway]

Ok I am beginning to get the feeling that I am crazy or going that way. So I go back out to the barn and pick out the old battery cable out of the other rusty junk pile from taking the tractor a part. The battery cable which is RED was attached to the frame on my tractor! But taking a closer look there is a tag with a big minus sign on the cable which was under grease and junk. I looked at the battery and it would have had to be red to negative terminal on the battery because of the length of the cable. The black cable went from the positive battery terminal to the starter solenoid. I should have looked closer. My bad. Any way what is the "12" on #3 Alternator in your diagram?

 

[Kenneth S]

The 1, and 2 on the alternator just refers to those two terminals. Running a wire from the oil pressure switch to terminal 1 will excite the regulator/alt to start charging right away, if you don't run that wire you will have to rev the engine up for a moment to get it to start charging. The terminal 2 hooked to the + will tell the regulator the voltage so it won't overcharge the battery.

 

[Inolaway]

The 1, and 2 on the alternator just refers to those two terminals. Running a wire from the oil pressure switch to terminal 1 will excite the regulator/alt to start charging right away, if you don't run that wire you will have to rev the engine up for a moment to get it to start charging. The terminal 2 hooked to the + will tell the regulator the voltage so it won't overcharge the battery.

My alternator does not have that. It only has the one termina on the back, nut and bolt set up. It has a grounding screw bolt at about 7 o'clock. There is black plastic cap on top of the alternator would those terminals be under there?

 

[Kenneth S]

They would be under there. but as you know electrical components are constantly changing, it could be setup to where you don't need to hook those up anymore. I haven't seen one of those with that type of cap on them yet.

 

[Inolaway]

They would be under there. but as you know electrical components are constantly changing, it could be setup to where you don't need to hook those up anymore. I haven't seen one of those with that type of cap on them yet.

From the diagram it appears they are both positive is that correct?

 

[Kenneth S]

Yes they are both positive, since yours has the cap I'd just hook up the one wire the + on the alternator, it should work as it is.