B2 won't crank with key but will on solenoid

[Craig_S]

I bought an 89 B2 for $100 earlier this year and I'm just getting around to planning the build. Before the engine swap I want to figure out why I have this problem. The engine won't crank with the key, but if I do the old Ford "solenoid bump" (short a screwdriver across the terminals), it'll turn over and fire up. I'm assuming I have a problem with the S wire, correct? Any advice on what to look for? Pics of your 89/90 solenoids, etc might be all I need.

Thanks,
Craig

 

[duffy]

Bad ignition switch perhaps......I had a 77' F250 that had that same problem and it was the key switch.

 

[Craig_S]

Thanks, I'll check that.

 

[jsp1946]

Did you figure this one out? I had the same problem, only 7 volts at the signal wire. Turned out to be a very nasty, PS fluid coated connection on the engine bay harness.

 

[Craig_S]

Thanks for replying. No I did not figure it out. I ended up pulling the driveline and interior out to start my build and just counted on putting a new ignition switch in it when I get to that point. Hopefully that takes care of it!

Thanks, Craig

 

[darkd0r]

1980's ford ignition switches are notorious for coming apart with varied symptoms.
The '80's headlight switch (which contains the circuit breaker) is also a known weakness. Causes the breaker to trip with the high beams, and as time passes, with just low beams. Has happened to my F150, Lincoln Town Car , and an '83 Mustang. Solution is to wire headlights through a relay so that switch only carries the current of the relay coil. Gives you brighter headlights, too.