Michael Lewis

The switch didn't do anything with the smaller wire hooked to the other terminal

88xlt

Ok let's back up a bit. Now if you take something metal and bridge the 2 large posts on the solenoid the starter should spin. You need to use something heavy enough to carry the full current to operate the starter, ie something as big as the inside of a battery cable. Does it spin the starter?

Chris_1

iTrader: (1)

The small boot looking wire that plugs on should only have power when the key is at 'start'.
No other time.
If you have constant power there that indicates a fault in the circuit most likely back at the ignition switch on the column.
If you've had constant power there for a while it's probably burned out the solenoid by now.

Michael Lewis

Even with a brand new solenoid? And how do I trace where the problem is? I don't have a multimeter, just a test light

Michael Lewis

Sorry about the late response, I've just barely finished moving and I'm still trying to figure out this issue.

SO when I turn the key to START, the EMISS light comes on the dash, as well as the BRAKE light. The truck doesn't start.

If I have the key in the RUN position (truck not started), and I bridge the two terminals on the solenoid with something heavy enough, the truck will start.

There is constant positive voltage to the small boot looking wire that goes into the solenoid.

Also, if I leave the battery connected, the next day, it'll be dead. I'm assuming that's because of the constant positive on that boot wire.

Not really sure where to look next, however, I'd really love to get this thing fixed.

Chris_1

iTrader: (1)

The small plug on (boot looking thing I think you called it) should ONLY have power when you turn the key all the way to 'start'. No other time ever.
Power at that wire activates the solenoid and makes the starter turn.
If you have power there all the time it will burn out the solenoid.
Power to that wire comes from the ignition switch which is a white rectangular box on the bottom of the column on 92 to 96 trucks. I think it's on top on earlier trucks.
You probably need a new ignition switch and another new solenoid.

Michael Lewis

That's sort of what I was thinking, thanks so much, I really appreciate the help a ton!
I'll have to replace the ignition switch and see if it helps. Do you know if it'd be compatible with one from a '75 f100? I've got one that I'm planning on restoring in the near future that I'd be okay with pulling the ignition switch out of, if only to make sure that's the problem.

Thanks

Chris_1

iTrader: (1)

88 to 75 ? Not even close.
Buy a new one. It's the first thing a mechanic is going to go to and a switch will be cheaper than an hour of shop time (after you get frustrated and drop it off there).
If that's not it you'll have a spare.

Michael Lewis

Swapped out the ignition switch, as well as the lock cylinder since mine had been having issues anyways. It'll still start with the key to "run" if I jump the starter solenoid, but not if I turn it to "start". There isn't a constant positive at the boot wire on the solenoid anymore, would the next step be to replace the starter solenoid and find out if that works?

Michael Lewis

When I try to start the truck via the key, the brake light comes on, but only while the key is turned to start