Oliver 1550 Solenoid Wire (White)

Looking at the Oliver 1550 shop manual schematic, there is white wire from starter solenoid going to wiring harness, anyone know where the white wire terminates. Looking at the diagram there is white wire terminating at the positive side of the ignition coil and also joins with an orange and purple wire inside the wiring harness. My rebuilt starter has a three post solenoid (where the white wire would connect on solenoid) as the diagram depicts. I am told by the starter mechanic no need for the fourth post on the solenoid as it is only used for grounding and the new solenoid grounds to the starter housing. Without a white wire from the solenoid to the coil I plan to run a white wire from the ignition switch "I" post to the ignition coil. I am using the diagram from another post (rvirgil_KS Oliver 60 Need Wiring Help !!!) to complete the starter solenoid wiring. Anyone see problems in this method on the Oliver 1550 Gasoline.

The forth terminal (on a Delco) would be marked "R", and is NOT a "ground, but rather is "hot" while the solenoid is engaged to bypass the ignition ballast resistor for hotter spark during cranking.

I would get the correct solenoid, if you choose not to, simply insulate the unused wire and leave it.

If the tractor run before, it will run like that, just won't have the "starting bypass" functional.

If the tractor DOES use a ballast resistor or ballast wire and you run a wire direct from the coil to the ignition switch you will overheat the coil and burn the points.

(quoted from post at 13:07:14 08/20/16) The forth terminal (on a Delco) would be marked "R", and is NOT a "ground, but rather is "hot" while the solenoid is engaged to bypass the ignition ballast resistor for hotter spark during cranking.

I would get the correct solenoid, if you choose not to, simply insulate the unused wire and leave it.

If the tractor run before, it will run like that, just won't have the "starting bypass" functional.

If the tractor DOES use a ballast resistor or ballast wire and you run a wire direct from the coil to the ignition switch you will overheat the coil and burn the points.

Click to expand...

Bob, thanks for your reply. Looking over the schematic I don't see a ballast resistor or wire.

Anyone recommendation where to purchase the correct starter solenoid for the Oliver 1550 starter, Napa or other vendor brand that would work for this application?

Some mfgs used a resistance wire. I do not know if Oliver did. It is possible the wire at the coil with the white wire IS a resistance wire.

Try this... with breaker points closed, and ign switch on, measure primary Volts at the coil.

If battery voltage, there's no resistor in the circuit, and the starting bypass is not needed.

If there's maybe 8 or 9 Volts, there's a resistor or a resistance wire in the circuit.

To find the correct solenoid, it would be nice to have the part number that was stamped on the original.

That white wire runs to the coil. Along the way the resistor wire from the ignition switch is soldered to the white wire just behind rear of the block on mine. It was all taped. Mine has an SI alternator (wired wrong) so the regulator is gone. I discovered this while straightening out the wiring. As I recall, the resistor wire is light gray (or white) and is long and very limp. It's doubled back and forth inside the taped area. When you start the solenoid closes the contact to the white wire an sends full voltage to the coil, bypassing the resistor.

(quoted from post at 13:55:25 08/20/16) Some mfgs used a resistance wire. I do not know if Oliver did. It is possible the wire at the coil with the white wire IS a resistance wire.

Try this... with breaker points closed, and ign switch on, measure primary Volts at the coil.

If battery voltage, there's no resistor in the circuit, and the starting bypass is not needed.

If there's maybe 8 or 9 Volts, there's a resistor or a resistance wire in the circuit.

To find the correct solenoid, it would be nice to have the part number that was stamped on the original.

Click to expand...

The Oliver 1550 shop manual lists a Delco-Remy starter 1107358 or 1108431 starter, but no solenoid part number. I located a couple of part numbers 101 059-AS and 159 684-AS for the starter switch, Delco-Remy part #s 1467 and 1114226. Although, these appear to be three post type solenoid. Part numbers are not cross-referencing for a comparable part.

Starter solenoid appears to be correct fit for Oliver 1550 tractor:
Starter Solenoid - Delco Style - 12 Volt - 4 Terminal, Delco Remy, 1114549. The four terminal version.

That white wire is a resistance wire to give you 12 volts for starting.

(quoted from post at 16:24:00 08/20/16) That white wire runs to the coil. Along the way the resistor wire from the ignition switch is soldered to the white wire just behind rear of the block on mine. It was all taped. Mine has an SI alternator (wired wrong) so the regulator is gone. I discovered this while straightening out the wiring. As I recall, the resistor wire is light gray (or white) and is long and very limp. It's doubled back and forth inside the taped area. When you start the solenoid closes the contact to the white wire an sends full voltage to the coil, bypassing the resistor.

Click to expand...

Comparing the Oliver 1550 schematic and your comment above, my wiring diagram reads as you describe. Just need to locate the resistor wire from the ignition. Pulling back some insulation tape wrapped around the harness. Thanks for the help.

I'm looking at a 1650 diagram.

As mentioned by others the white wire goes to + post on the coil

1650 diagram shows an orange wire coming from I (ignition) post on the switch going to the voltage regulator. There is another wire coming from I terminal on the switch. Follow this second wire into the harness and it should be connected to an approximate 2 ohm resistance wire.

As mentioned, the tractor uses a 6 volt coil with resistance wire dropping voltage and limiting current to protect the coil and points. White wire from start solenoid bypasses the resistance wire allowing full 12 volts for hotter spark during engine cranking.

You can tape off the white wire at the starter solenoid. Do not run a wire from + on coil direct to I terminal on switch. This will bypass the resistance wire which will damage points and coil.

I wonder if your starter man is thinking about a different type of solenoid when he says the extra post is a ground.