Dead ignition switch

[Gitche Gumee Kid]

My IH 284 diesel ,that I bought new in 1980 ,has never failed to start in all those years. Yesterday , the ignition switch was dead . Battery was charged. No change. After removing some sheet metal to gain access to back of ignition switch, I found I had current to center post of switch. Using a continuity tester ,I Turned switch to on,start and glow plug . No current show.

I don't want to buy a new ignition sw if not needed . What else needs checking. TIA

GGK

 

[Rebeldad1]

Using a volt meter key off. check voltage at center + post. Now check all others.

key on check all posts again. you should have a voltage drop at the + post and voltage to acc posts. This should tell you what your key switch is doing. If + post voltage drops very low or zero you have a bad connection to the switch.
Also check voltage to fuse panel with key on and key off. without a wiring diagram Im not sure what key functions are.

 

[radios1]

think about it, if the center post don't connect to anything, there's a problem with the switch!..

 

[PILOON]

I have revived quite a few switches.

I had opened some to find they were actually OK but not making contact.
They all use a small spring to assure contact and add a dielectric grease for lubrification.

Over time the grease dries and hardens to the point that the contact spring can't overcome the resistance.
My solution has been spray WD40 into the key slot and to vigorously actuate it.
The WD40 dissolves the grease enough to restore them back to like new action.

(WD40 will not cause corrosion and is safe in this application.)