I have a 1989 F-150 that is boggling my mind. Today replaced starter b/c it was not engaging the flywheel. Tested the small terminal at the solenoid and it was reading over a 1 volt drop. Fixed that gremlin! So I could then jump the solenoid next to the battery and start the heap. (The ignition switch (key) would not start the truck.) So I tried to chase that down with a new ignition switch in the column and that DID NOT help. I can not understand why it wont start. The transmission will not come unlocked out of park as well. I checked all positions of the key (ACC, run, and start) They all work correctly but it wont start. Should I trace the wires from the ignition switch in the steering column? They appeared to be fine. In addiition when I place the ignition switch to start position the middle wire that connects the solenoid (by the battery) is NOT reading voltage to connect the battery to the starter. Should that middle pin or wire read the same 12V the battery is putting out? I though that is what that does is bridge the gap from the battery to the starter solenoid/motor? What a can of worms.....Any suggestions would be greatly appreciated. I need to move the truck soon or it will be towed.
thanks in advance -
Glenn

 

You may have a problem with the linkage in the steering column.

I do not know if you realize this, but the actual electrical part of the ignition switch is mounted on top of the column, underneath the dash. The keyswitch that you turn is just mechanical. There is usually a little piece up in the column that breaks, and will not push the actuator rod enough to start the truck.

What you can try is taking the shrouds off around the column. Turn the keyswitch, and you should see a small metal rod on top of the column move. Turn the keyswitch to start, and then take some pliers and grab the rod on top of the column, and "help" it move down with the keyswitch. See if this will make it start.

You also have a neutral safety switch on the tranny. This can go bad and let it not crank also. If you need to move it, you should be able to put the key in the run position, and then jump the solenoid like you were doing to get it started. As far as the tranny interlock, that is usually caused by a blown fuse.

 

If the tranny is locked. Wouldn't that be part of the linkage problem also? If that rod does not move all the way down. I don't think the tranny will unlock.

 

I know it locks the steering wheel, but I thought the tranny lock was a electrical solenoid that is activated by the brake switch. I am not sure to tell you the truth, but it does unlock when you push the brake pedal.

Come to think of it, his truck may be to early a year model for the brake interlock thing. It may be related to the column.

 

Where is that solenoid that controls the interlock? Is the fuse that protects the solenoid in-line some where or in the main fuse box under the dash? I understand the bar on top of the column not engaging the ignition switch in full down (start) position. Bought a replacement switch and that didnt work. I was going to unlink the linkage (under the brake booster) to isolate if it was still in the column or in the tranny itself. If I could find that solenoid or fuse, I will do that next. Thanks for all of your replies....

 

What is the easiest way to seperate the tranny linkage at the booster. THat pressed bushing is a beyatch!

 

Tried the brake switch and the neutral switch. The press-in bushings on the bar-style linkage is difficult to get off. I have to go to the transmission place tomorrow to get the tool to take those bushings out. I really think the tranny is locked-up.

 

If you think it's the neutral safety switch, which is located on the side of the tranny where the linkage enters the tranny, you can crawl under the truck, unplug the safety switch plug, and jump the two red/blue wires together. That will bypass the neutral safety switch.

 

Dave thanks. That is exactly what we did and we deduced that the nuetral safety switch was bad as well as the output to the starting solenoid. I guess who worked on it before messed that female adapter up a bit. Thanks for all of everyone's help. The transmission problem now is the fun part. It still will not shift out of park. We disconnected the tranny linkage; and it still will not shift by hand. We rocked the truck and tried to force it. We also diconnected the driveshaft to reliece all stress on the output shaft. I think this thing was towed while in Park. So, I guess I will drop the old C6 and take her in to see what the damage looks like on the inside.