I had my shutdown solenoid off of my '95 the other day and when i put it back on it didnt work. I have checked and double checked, everything is in place, hooked up etc. so i figure maybe the relays or the lead to the battery has gone bad. i put a volt meter on the 3 wire harness that hooks to the solenoid. with the key in the run position one of the 3 wires has power. so then i did the same thing on my '97 and thats how its supposed to be. i figure its gettin power, so the solenoid itself must be bad, but i swapped it onto my '97 and it works on there. so im officially stumped what am i missing? what else can i check? thanks guys.

 

I'm going by memory , also my truck has 2 relays , the ing. sw. can not handle the load so the way it work is , the ing. sw. closes the ground to the relay coil , that energises the coil and pulls th points to conntact , so the heavy load is coming from the relay , then theres 2 circuts between the relay & solinoid , one is a [ pull on ] in the start pos. and then a [ hold ] in the run Pos.
Then there is a comin wire going to the starter , this is where some guys mod to make the system better , getting a heavy diode installed at the starter [ larry Bs ] so that if the contacts stick in the starter solinoind , it will not burn out the fuel solinoind .

 

you have 3 wires and 2 circuts there.

one circut comes from your starter contacts and is only hot when you crank the starter. this is your "pull" circuit.

the second circut comes through your keyswitch in the "run" position this is your "hold" circut.

both of these come through relays on your firewall above your bake powerboost.

the wire that you have power to when the keyswitch is on is your "hold".

check the other two for power when you crank the starter. this would be your "pull".

If you get power to both pull and hold it could be the solenoid or your ground.


i'll find the diagram in a few...

http://www.fostertruck.com/images/st...it_diagram.jpg

 

yeah, i have power to the "hold" circuit, but with the keyswitch on if i pull up the plunger it still wont hold it up. i know the solenoid is good cause i checked it on my other truck and it holds. looks like the ground, where is it grounded at? thanks.

 

If you have a DVOM or an Ohm Meter there , check the ground wire for continuity to ground.

 

looks like the brown/black wire, poke it and check for continuity to the frame.

 

checked ground wire with ohm meter, its good... zeroed out when i hit the neg battery terminal. its really lookin like the solenoid itself is bad, maybe tomarrow i'll pull it off and double check it again, but it worked fine on my other truck like 2 days ago thanks for all the help so far guys

 

also, check the connection of the ground wire on the solenoid itself. for that matter, check the pull and hold too.

sometimes the connections/connectors will be corroded.

 

There is no relay for the hold circuit, juice comes though the key switch. The second relay on the firewall is for the fuel heater.

The way your problem sounds the key switch or the wiring is most likely the problem.