wilson switch suddenly shorting out??? (1 Viewer)

[flyfishbc]

i have my wilson switch hardwired, battery to fuse to switch to glowplugs. it has been fine for 4 or 5 months, worked fine this morning, then after work truck wouldn't start. tracked it down, fuse keeps blowing on wilson. looked at wiring and nothing looks like it should short out, but do not have a continuity tester. if a glow plug is fried would it blow the fuse. i need some help here, not sure how i'm gonna get it started in the morning.

 

[simonliew]

Did yo uwire the glowplugs directly thru the wilson switch to battery without a relay??
The contacts on the switch might be fried.
l usually use the factory relay,all you need to change on the factory relay is supply power to the solenoid wire and wire the ground thru the wilson switch.
like :fusuble link to relay,relay to glowplugs,on the two small solenoid wire,one to power and the other to ground thru the wilson switch.
Simon

 

[flyfishbc]

no, i didn't use the relay. just directly through the switch. i am not sure where the relay is. i can hear it , but can't find the **** thing. it was also bloody cold when i wired it, will rewire in a couple weeks, when it warms up

 

[simonliew]

What series truck is this?
Simon

 

[flyfishbc]

do i have to say it? its an lj78

 

[flyfishbc]

do glow plugs ,themselves, ever short out ? if 1 is fried, would it not draw less amperage, cuz only 3 are drawing current. i changed the switch and the wiring.from the battery to the switch, and from the switch to the buss bar. still blows the fuse. 25 amp fuse, the same as i have run for the past few months.

 

[flyfishbc]

PLEASE HELP. wiring all new ,glow plugs new, switch new, still blowing fuse. there is an insulator or spacer between bus bar and hot lead. it is cracked but i epoxyed it.

 

[markhc]

I just took a look at my truck and I think the relay you're looking for is located near your battery. My relay is round about the size of a walnut. Have someone turn your ignition on while you listen and you should feel and hear it click. there will be four sets of wires on the relay. The smaller pair of wires should be the wires that enable the relay to turn on the glow plugs. Of the two smaller wires you will want to identify the (+) 12VDC wire. This smaller wire is probably wired in series with a timer. (or infact that relay is also a timing relay, therefore you may have to replace the entire component.) So when you turn your ignition on, the timer enables the relay and then times out. I would simply cut the small positive wire attached to the relay and put in a manual switch to this wire. Cap off the cut wire coming from the timer.

This is only what I can see, I haven't pulled out my multimeter to measure the voltage present at the relay. In fact I've never traced the wiring out for this portion of the vehicle, I'm just using my electronic controls experience to assume what the truck engineers have done. I'll look at my wiring manual and see if my theory is correct.

 

[flyfishbc]

cool, thanks. will give it a go.