Need Cub 48 wiring schematic

Sat Jun 05, 2004 9:03 am

I'm a new Cub owner with starting/charging problems and would like to have an original wiring schematic for a 1948 Cub SN: 18268
I've seen alot of schematics out there but they're all a little different then how my Cub is set up:
1. 3-position light switch
2. cutoff relay (not a regulator as forum members have told me) ontop of generator...voltage regulated by light switch?
3. push-pull, run/kill plunger switch with push to start button ignition switch ....another words I don't have the common starting switch control rod I've a starter relay ontop the starter?
4. 20amp fuse is located behind the light switch
5. "F" on generator is connected to cutoff relay

Sat Jun 05, 2004 9:09 am

Maybe this will get you started.

You may have to change/omit a couple of things on your cub.

got that an more

Sat Jun 05, 2004 9:16 am

Cub-Bud, Thanks for the reply, got that one and others.always a little different.
Yea, I can work off of the ones out there in cyber space, but this set-up I've got is tricking me a little.
I'd like to see if my Cub has been modified in some after inspecting the previous owners wiring and abundance of paint overspray!

Sat Jun 05, 2004 9:30 am

9mules, a 4 position light switch would have been orignal for your cub. The 3 position switch wasn't used until the cutout on top of the generator was replaced with a voltage regulater that was mounted elsewhere. Likewise, the starter relay wasn't used. Is your push-pull switch a 1 wire (magneto) or a 2 wire (distributer)? Are you sure the switch is 3 position and not 4 (count all the positions the switch cna be turned to). I am not up on exactly when some of the changes were made, but I thought that when the 3 position switch came into use it required a fuse mounted in the dash rather than still having one made as part of the switch. Wuth the F terminal from the generator connected to the cutout I assume it will only charge a max of 1 or 2 amps.

Sat Jun 05, 2004 10:13 am

Also keep in mind, that a 4 position switch will only hit 3 clicks when you turn it. You count the place where you start as one, then each notch is 1, and then the stop on the other side as 1. . Maybe this is causing confusion?

In other words, a 4 position will feel like it moves 3 times when going from one side to the other. A 3 position swithc will feel like it moves 2 times.

Sat Jun 05, 2004 12:49 pm

One other thing to check.....make sure the dash has a good ground to the torque tube. The guage grounds to the dash and the dash to the torque tube. In order for the guage to work/show charge, it must be grounded. 8) I learned this by reading Jim Becker's article in Red Power Magazine a few issues back. :wink: Thanks again for that article, Jim. :D

Sat Jun 05, 2004 1:30 pm

OOPS.....I stand corrected :shock: :!: The dash needs be grounded to the torque tube in order for the SWITCH to work properly, not the guage. Sorry :!: :oops: :oops: :oops:

dead now

Sat Jun 05, 2004 2:55 pm

Charged my battery up, installed it and fried the positive cable(ground) after it ran for a few seconds....whenever I touch the postivie cable to ground it sparks and fries.


Sat Jun 05, 2004 4:28 pm

Light switch labeled: O,D,B, thats it, ...but counting the clicks...I got 4 clicks.
First is O then etc.
Whats causing the positive ground to fry? I know the answer but damn...every time I touch this rig something ain't right.
Hmmm...ain't this fun.
Cub-Bud I ain't got a clue what a torque tube is on this rig.
Hug Your Cub

Sat Jun 05, 2004 6:18 pm

The torque tube is the casting between the transmission and the engine, it includes the clutch housing, and the dash fastens to it. Make sure you don't have a bare spot in the insulation of the battery cable going to the starter. If the retainer clip is missing, they can easily be rubbed through by the clutch pedal.

Thanks now what?

Sun Jun 06, 2004 11:45 am

Thanks for the info...finally crawled all over the Cub for the first time and found out all kinds of things. I like that removable clutch inspection plate.
1. Clutch pedal ate the battery cable...fixed it...and starts right up.
2. Now the Cub's ampmeter is reading a discharge of 12-18 when the lights are turned on and about a 2-6 at slow idle without lights on.
4. Need to check to see that amp meter wires are connected correctily.
Should I polarize...would this correct the amp readings?

F terminal culprit

Sun Jun 06, 2004 11:03 pm

After fixing the ground cable the ampmeter was still showing discharge and I couldn't get the polarization spark....inspected the generator wiring by pulling the inspection ring off and found the F terminal wire wasn't connected....fixed that and got the infamous polarization spark and now the ampmeter reads its charging!
I hope this has finally fixed my Cub...thanks for all the help everyone!

Mon Jun 07, 2004 9:20 am

Congratulations on getting your problems fixed. Sometimes it gets frustraing, but it feels good when it finally comes together doesn't it.

Phase 2

Mon Jun 07, 2004 11:47 am

Sure was frustrating but the knowledge gain (though it'll make you feel homicidal) in hindsight was worth it.
I'm still not comfortable with the electrical...just a little hard to start in the morning...need to run longer, making sure I've full charge & go through the wiring cleaning all ground connections.
Paint overspray is a killer!
Phase 2:
Find out why I've lite blue smoke (oil) and a slight knocking sound in head area.
Will change oil, use Sea Foam, research forum and download tech manuals.
Doesn't hurt to hug your Cub and ask it what it needs!