Electrical Ghosts
Thread Starter
|
Cross-Country
Joined: Mar 2016
Posts: 54
Likes: 7
Electrical Ghosts
Well....I don't post much....unless I get stumped....and I'm stumped.
I have a 1991 F250 that I've had since it was born, so I'm pretty familiar with it.
I have a no start issue that is confusing me.
In the past I've replaced the Ignition Actuator in the steering wheel (more than I like to admit) so I tore it down and it's working like it's supposed to.
So...figured it must be the clutch interlock switch.....but I bought a new one and that isn't it either.....and it takes a young guy or a contortionist to replace that little piece of hardware!
I can start it with a screwdriver across the solenoid.
Besides the pot metal piece of junk in the steering wheel and the clutch switch.....what else is involved in getting power to the solenoid?
I'm wondering what that ignition actuator does when you turn the key.....what does it contact?
Scratching my head .....and can't find a decent schematic.
I have a 1991 F250 that I've had since it was born, so I'm pretty familiar with it.
I have a no start issue that is confusing me.
In the past I've replaced the Ignition Actuator in the steering wheel (more than I like to admit) so I tore it down and it's working like it's supposed to.
So...figured it must be the clutch interlock switch.....but I bought a new one and that isn't it either.....and it takes a young guy or a contortionist to replace that little piece of hardware!
I can start it with a screwdriver across the solenoid.
Besides the pot metal piece of junk in the steering wheel and the clutch switch.....what else is involved in getting power to the solenoid?
I'm wondering what that ignition actuator does when you turn the key.....what does it contact?
Scratching my head .....and can't find a decent schematic.
Cargo Master
Joined: Jan 2004
Posts: 3,118
Likes: 149
From: South Dakota
Which 2 posts on the solenoid are you bridging? If you are bridging the 2 large terminals on the solenoid, you are bypassing the solenoid ie the engine will turn over even if the solenoid is faulty. To test the solenoid, bridge the terminal on the solenoid with the cable that hooks to the positive battery terminal to that little pull off terminal on the solenoid that has the pull off wire when the wire is removed.
The solenoid itself may not be your problem at all, just something to check. And if this is what you are doing you are already checking the solenoid.
The solenoid itself may not be your problem at all, just something to check. And if this is what you are doing you are already checking the solenoid.
Hotshot
Joined: Jul 2020
Posts: 10,317
Likes: 2,581
From: Near Salt Lake City
The ignition switch is what is left
Your ignition switch may be coming apart at the seams
A 1991 EVTM will show your start circuit
There will be a jumper wire at the takeout for the wiring that would be there for an automatic trans
Just like there would be a jumper at the clutch interlock switch if you had an automatic trans
So, find the automatic trans jumper / shunt, verify it is plugged in and there is power there when in crank
Same with the clutch interlock, check for power there and work your way back to the ignition switch
Try wiggling the ignition switch connector wires around while turning the key to start
See if the ignition switch is about to start a fire (like they did before the biggest recall in the history of recalls)
Your ignition switch may be coming apart at the seams
A 1991 EVTM will show your start circuit
There will be a jumper wire at the takeout for the wiring that would be there for an automatic trans
Just like there would be a jumper at the clutch interlock switch if you had an automatic trans
So, find the automatic trans jumper / shunt, verify it is plugged in and there is power there when in crank
Same with the clutch interlock, check for power there and work your way back to the ignition switch
Try wiggling the ignition switch connector wires around while turning the key to start
See if the ignition switch is about to start a fire (like they did before the biggest recall in the history of recalls)
Fleet Owner
Joined: Oct 2005
Posts: 20,783
Likes: 1,751
From: Kentucky
1991 Start Circuit diagram from Operation CHARM:
Ignition Switch test procedure for a 1990 model year truck. Should be the same for your 1991:
Ignition Switch test procedure for a 1990 model year truck. Should be the same for your 1991:
Thread Starter
|
Cross-Country
Joined: Mar 2016
Posts: 54
Likes: 7
Well.....never mind....it was installer error.
I removed the clutch interlock switch and re-installed it and now it works.
There is a step in the clutch rod that has to be behind the step in the switch.....you can't just put it on the rod.
It's a tight, cramped area for a big guy and I rushed it I guess.....after it was installed correctly it started right up.
Thanks to those that replied and tried to help.....I appreciate it.
I removed the clutch interlock switch and re-installed it and now it works.
There is a step in the clutch rod that has to be behind the step in the switch.....you can't just put it on the rod.
It's a tight, cramped area for a big guy and I rushed it I guess.....after it was installed correctly it started right up.
Thanks to those that replied and tried to help.....I appreciate it.
Thread
Thread Starter
Forum
Replies
Last Post
b.simone1210
1978 - 1996 Big Bronco
2
Jun 23, 2013 12:13 AM
jfoltz
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Nov 29, 2009 11:19 AM
