ih234 Ignition switch starting issues HELP!

[diggs00]

Installed new ignition switch and she started up fine. Changed all fluids (oil/trans/hyrdo) then went to start it and it cranked then suddenly stopped. I jumped the PTO and the Gear solenoids to rule them out. Still nothing, no starter solenoid click nothing. Placed wire on + battey terminal to starter solenoid, it clicked so ruled the starter solenoid out.

Testing aftermarket ignition switch:
Tested on the bench, the B terminal reads voltage, with key in the start position the C(ST) terminal reads voltage so this looked good to install.
Now when installed on tractor the B shows voltage but with key in start the C(ST) reads nothing. I am going out of my mind , spent 2 days on this and went through 4 ignition switches! HELP!!!

 

[used red MN]

On the tractor what does the voltage show between the terminals that clamp around the battery post? What does the same show when you turn the key to start? If it goes to zero you have a bad connection in other words the inside of the terminals or the outside of the posts have crud on them that are not letting them conduct current. If that is good the test would be between the opposite ends of the cables at the bolts or terminals they connect to. If the voltage drops there when you move the key to start then a cable is bad. To test the cables put the meter leads on each end of the cable and hit the start and if you meter shows battery voltage then that cable is bad. I don’t understand how your solenoid clicked when you powered it be the engine did not turn? Maybe you had the starter disconnected. This is pretty brief but I don’t have much time. Here is a wiring diagram if that helps.
IH 234 wiring diag.
Maybe be back later.

 

[diggs00]

Thanks for reply!
I will test the cables tomorrow.
To test the starter solenoid all I did was have key off and touched wire to small starter solenoid terminal and the battery +, it clicked but the starter did not engage.

Question:
Using multimeter I get 12volts on the ignition switch on terminal (B). When I then move key to start, why is the ignition switch start terminal (ST) 0 volts? Shouldnt the B terminal voltage be transferred to the ST terminal?

 

[used red MN]

Ya but if you have a bad connection somewhere it may carry enough current to make your meter read the voltage. That requires a very small amount of current measured in amps actually milliamperes in this case. When you add the pull or load from something that requires more amps the connection may not be able to carry the load so the voltage drops. The lack of a proper connection is called resistance. Your problem may also be a poor connection between the chassis and the lug on the end of the ground cable. Take it off and sand the surfaces shinny.
The main cable checks are just a starting point. The faulty connection could be in any wire or connection. It is a matter of systematically checking it until the trouble is found.

 

[diggs00]

@used red MN
Ok I put new negative and positive cable on new battery, cleaned up the starter power prong and the chassis ground.
Still no voltage coming from igntion switch (ST) terminal when key in start postiion. I get power coming from (ACC) terminal, so i decided to hook up the wires form the ST terminal to ACC. Tractor starts right up.

Why would the switch not transfer power to the ST on key start, bench test it does!!! FIrst igntion switch i purchased worked for a while in ST terminal then quit. 2nd ignition switch nothing, third switch nothing. Is there a OEM 5-6 post (glow plug) ignition switch out there that is not from CHINA!

 

[used red MN]

As long as your meter is showing voltage on the battery terminal of the switch and it maintains it when you goe to the start position but then does not transfer it to the start terminal the problem is in the switch.
Brillman has been known to have quality parts.
Brillman switch
And one is available through CNHI, fairly spendy.
CNHI IH 234 switch