Trying to understand my glow system (1 Viewer)

[pescado]

I am trying to troubleshoot my non functioning glow plug system on my Nov 1985 24v HJ60. The previous owner put in a Wilson switch, but it never worked as long as I have had the truck. It stays warm year around here in Hawaii, so I believe it has been able to start up without a functioning glow system.
But I would like to get it working and need some help trying to figure out what the previous owner did and what's wrong with it. Here is a breakdown of what is in place:

The Wilson switch on the dash has two wires coming off it. The red wire goes from the switch and plugs into the fuse box under the DS dash. What does this red wire plug into?

The black wire from the Wilson switch goes under the dash, through the firewall, and into the glow plug solenoid in the engine bay.

The glow plug wire goes straight to the the glow plug busbar and bolts right to it directly.

With the key in the on position, and the Wilson switch pressed, there is no voltage that goes to the glow plug busbar according to my multi meter.
If I jump the glow solenoid with a wire, I can get voltage to the glow plug busbar (20.7 volts). So I am assuming the Wilson switch is not engaging the glow solenoid? I have hooked up a new 24v glow solenoid and I get the same no voltage results. Anyone have any idea what could be wrong with this setup? Anywhere specific I can start troubleshooting?

 

[pescado]

Here is another view of the glow solenoid.

I still can't figure out what that mystery wire is. It disappears into the main wire harness and I can't tell what it goes to.

 

[tornio]

hi, you can start checking if there is + 24v on the red wire that come from the fuse box

then check that the switch is working right : when activated you must have +24v at the selenoid input

then check the other wire coming from selenoid that goes to ground is "really" grounded , selenoid input grounded.

if yes your selenoid must work if not defective

take a look

about the "mistery wire " : if you want to run "Wilson Switch" style and your glow plug are correct for this method , cut this mistery wire
(or disconnect it from the selenoid ) and simply run from selenoid to busbar...

hope it help

 

[pescado]

Thanks, that is very helpful. You were right with the first check, no 24v power to the red wire on the fuse box. The pin next to it had 24v, so when switched red wire over to it, the solenoid gets power now. No more hard starts anymore, thank you very much for your response.

By the way, I looked at google photos of Ornavasso Italy, and it looks like very beautiful scenery. I will need to visit that region someday! Molte grazie.

 

[tornio]

perfect ! happy you solved ! thank's for compliments about my region .. and yes if you like mountains and lakes here is beauty !

ciao cheers