Wiring a C

Help. I bought a reproduction wiring harness for my "C" and am having horrific problems. It seems that there is no single schematic for the "C's" as there are so many variations: cutout vrs regulator, magneto vrs distributor, 3 positon switch vrs 4 position switch, etc etc. Here is what I have: 1950 C 6volt, head lites and tail lites, cutout, three position switch, and distributor. The biggest question: one diagram has the wire from generator "F" to the 4 position switch. Another has the wire from generator "F" to cutout terminal "F". Which is correct? Note that while my operators manual depicts a 4 position swith, mine is only 3. IF the generator "F" wire goes to the switch, where to attach it?

Many thanks in advance; I have a parade Saturday and the County Fair is coming up soon and I have to get things rolling.

cutout, three position switch,

Click to expand...

Right there is your first problem. A cut-out and a 3 position switch isn't a valid combinaton. You can make it work but the combination won't be in any original wiring diagrams.

You need to start by making sure what you have and deciding if that is what you want.

Jim has you started in the right direction.

If you have a 2 terminal (BAT GEN) Cutout Relay (versus a Voltage Regulator), then you need a 4 position (LHBD) Combination Light Switch and Low/High Charge Control NOT a 3 position (Off Bright Dim) Light Switch. If you had a 4 position Light Switch (correct for Cutout Relay systems) the Gennys FLD post wires up to that switch buttttttttt on the 3 position light switch, that system uses a Voltage Regulator which is to where the gennys FLD post wires

If you have a 3 (BAT ARM FLD) Terminal or a 4 Terminal (BAT ARM FLD LOAD) Voltage Regulator, then the gennys FLD post wires to FLD on the VR and you only need a 3 position Off Bright Dim headlight switch (i.e. no provision for the gennys FLD post wiring on the 3 position light switch)

EITHER system can be made to work, but if you wanna use that 2 terminal Cutout Relay then you need the 4 position Combination (lights & charge)LHBD Light Switch, as it regulates the charge. If you used a VR, then you only need a 3 position Off Bright Dim light switch (while the LHBD could still be used for lights ONLY butttttttttt thats NOT Hoyle)

John T

Jim has you started in the right direction.

If you have a 2 terminal (BAT GEN) Cutout Relay (versus a Voltage Regulator), then you need a 4 position (LHBD) Combination Light Switch and Low/High Charge Control NOT a 3 position (Off Bright Dim) Light Switch. If you had a 4 position Light Switch (correct for Cutout Relay systems) the Gennys FLD post wires up to that switch buttttttttt on the 3 position light switch, that system uses a Voltage Regulator which is to where the gennys FLD post wires

If you have a 3 (BAT ARM FLD) Terminal or a 4 Terminal (BAT ARM FLD LOAD) Voltage Regulator, then the gennys FLD post wires to FLD on the VR and you only need a 3 position Off Bright Dim headlight switch (i.e. no provision for the gennys FLD post wiring on the 3 position light switch)

EITHER system can be made to work, but if you wanna use that 2 terminal Cutout Relay then you need the 4 position Combination (lights & charge)LHBD Light Switch, as it regulates the charge. If you used a VR, then you only need a 3 position Off Bright Dim light switch (while the LHBD could still be used for lights ONLY butttttttttt thats NOT Hoyle)

John T

If you have a 2 terminal (BAT GEN) Cutout Relay (versus a Voltage Regulator), . . .

If you have a 3 (BAT ARM FLD) Terminal or a 4 Terminal (BAT ARM FLD LOAD) Voltage Regulator, . . .

Click to expand...

John,
You are right except for one detail. The cut-out relays used on most IH tractors have 3 terminals. It includes a FLD terminal that is unused on tracors that have lights. As far as I know, all the regulators had 4 terminals.

Just to build on the excellent advice below, and as briefly as I can . . .

With the three position switch you have, a regulator would be in order. Its function is to sense the state of the load and battery, and balance those to keep the battery charged, thus the switch only controls your lights.

The 4-position switch was for manual regulation of the charge rate on the simpler relay. L(ow) charge and H(igh) charge -- lights off -- were the basic choices. When you crank the switch around to D(im) or (B)right, the charge resistor is taken ou of the circuit (same as in the H position) and the charge rate is reduced by the amperage drawn by the lights.

As was said before, decide what you want and wire accordingly. With the 3-position switch, a regulator would be the easiest way to go, but be prepared to deal with the reality that many (thankfully, not most, but still, many)regulators are bad right out of the box.

With regulators there can also be a polarity issue, which may come into play, with 6v being more typically + ground, and 12v being NEG. Eliminate some headaches by making sure what you buy is compatible to what you want/are set up for.

Youre right Jim, on the old Cutout Relays for non lights tractors the gennys Field still needed a ground somewhere and the cutout indeed provided it. I dont recall seeing 3 terminal Cutouts (with FLD) on the later tractors, not sure if or when IHC started using 2 terminal relays????????? I have NO IHC LITERATURE maybe Bob M has diagrams or info regarding it???

Thanks, fun sparky chat

John T

In the words of famous philosopher Forrest Gump, "Stupid is as stupid does", I find that I have a Voltage regulator rather than a cutout. I dunno how I screwed this up other than long hours trying to make a living. I will locate the diagrams someone posted on photobucket and go from there, hopefully without mishap. Thanks for your prompt and astute observations as well as your help. You guys are great! Really. I may be back...........

This works. You can adjust the third brush in the genny for ideal output.