key sw delima

[ol~horses 4]

my wheel horse B80 blew the starter solenoid and the starter key sw . the key switch also showed signs of age.

I ordered replacements and just reinstalled (or tried to) last nite.

The old key sw. is a 103990....the new one is a INDAK with the same number.

I  used a meter to check the two switches after I could not get the new one to keep the motor running...it starts when I turn the key but dies when I let go of the key, every time.

The old switch still works, but I don"t trust it after fire came out the weep hole in the bottom of the switch body!

I tested each switch seperately. with a vom  1 probe was clipped to the center stud on the sw while i checked continuity  between the center stud and each individual stud.

On the old switch i have 2 pins that read perfect on both start and run, and one that reads to a run pin...the last pin is empty

On the new switch I read perfect to 3 pins the other one  is empty.

When I try to start the unit with the new key switch it cranks over and sounds like it is running BUT  when I let go of the key the engine goes dead while the key is in the run position.

I have tested both switches/circuits several times with the exact results, and am confused, becuase the tractor did run ok  before...

suggestions?

thanks

ol~horses

[pfrederi 17,147]

The terminals are marked this would be easier if you indicated which ones you were testing.  B I S R and A.  In run you should have continuity between B and A,I,R,.

 

Put the switch in run position and see if you have voltage to the + terminal on the coil.

[953 nut 51,656]

As you put the plug onto the ignition switch be sure the terminals are sliding all the way onto the ignition switch terminals. This diagram shows the wiring for a battery ignition system using the 103 990 switch.

[ol~horses 4]

thanks...guess i was jumping the gun by hooking a meter probe to common and hooking the other  probe to a pin while switching between start and run while observing continuity?

I did however observe that the old(origional) switch and the replacement switches on and off wise, were Not even close, even tho their part # indicates that they should be the same ....gotta pick up some propane first...cold in the garage

~olhorses

[ol~horses 4]

should have asked sooner....anyone have/know the right part number for a B80 ignition switch...it is the 5wire one....for some reason I seem to keep finding NOT the right number.....yep, they may look similar BUT they don't work similar, ie same

ol~horses

[gwest_ca-(File Mod) 10,495]

Click on the picture

Garry

[953 nut 51,656]

3 hours ago, ol~horses said:

should have asked sooner....anyone have/know the right part number for a B80 ignition switch...it is the 5wire one....for some reason I seem to keep finding NOT the right number.....yep, they may look similar BUT they don't work similar, ie same

ol~horses

Presuming the electrical system has not been modified and is a battery ignition system you will need the 103 990 as shown in the diagram I shared with you.

[ol~horses 4]

103990.....many thanks!