80 F100 ignition problem
Thread Starter
|
Freshman User
Joined: Jun 2013
Posts: 37
Likes: 0
80 F100 ignition problem
I have a 1980 F100 w/ 4.9. recently did the Zf5 conversion.
Currently I have the following issue.
I tried to start truck and had no keyed (acc) power and no crank.
I tried to use the starter bypass from in the bay and it started and ran for about 2 min then shut off with again no power.
The next day it would not restart from either key or bypass.
Hardwired acc power was still available.
I assumed the brand new ignition switch had failed so i put another switch in. Same problem. Sometimes i can start it from the bay and sometime i can start from key but either way, it will randomly shut off and lose ACC and Crank power.
The only other thing i can think of is a short somewhere in the ignition system. Any ideas?
Also, the ears on the bracket that holds the steering column to the dash broke. is there a part number or a place to get a replacement for this because right now I have no way to hold the column up.
Thanks
Currently I have the following issue.
I tried to start truck and had no keyed (acc) power and no crank.
I tried to use the starter bypass from in the bay and it started and ran for about 2 min then shut off with again no power.
The next day it would not restart from either key or bypass.
Hardwired acc power was still available.
I assumed the brand new ignition switch had failed so i put another switch in. Same problem. Sometimes i can start it from the bay and sometime i can start from key but either way, it will randomly shut off and lose ACC and Crank power.
The only other thing i can think of is a short somewhere in the ignition system. Any ideas?
Also, the ears on the bracket that holds the steering column to the dash broke. is there a part number or a place to get a replacement for this because right now I have no way to hold the column up.
Thanks
Moderator
Joined: Jan 2001
Posts: 56,977
Likes: 2,733
From: Virginia
Junkyard will be your friend for the bracket. Did your truck have a automatic in it before you did the zf swap? If it did, how did you bypass the neutral safety circuit that went to the auto tranny switch?
Thread Starter
|
Freshman User
Joined: Jun 2013
Posts: 37
Likes: 0
Its always been a manual and ive never had a problem starting it. i even drove it when the swapvwas done
Moderator
Joined: Jan 2001
Posts: 56,977
Likes: 2,733
From: Virginia
Here is how the power flows through your truck. I would get a testlight and probe different areas to see where you are losing it.
Power starts at the large terminal on the starter solenoid. There will be a smaller wire there with a fusible link, and then this runs out, hits some other splices, and then runs in through the firewall on a yellow wire. The yellow wire goes near the ignition switch, and hits a splice. One leg goes and feeds the ignition switch, the other leg goes and feeds the fuse box.
If nothing will work, the first thing I would do is probe the fuse box with the testlight. Probe the brake light fuse and the interior lights fuse, these stay on all the time and are fed by the battery yellow wire. If you do not have power, then you know the problem is farther back, and I would go out and check the wire at the solenoid.
If you have power at the fuse box, then turn the key to run and probe the fuse box again. This time, probe the circuits that come on with the key, like the blower fan, wipers, etc.
Power starts at the large terminal on the starter solenoid. There will be a smaller wire there with a fusible link, and then this runs out, hits some other splices, and then runs in through the firewall on a yellow wire. The yellow wire goes near the ignition switch, and hits a splice. One leg goes and feeds the ignition switch, the other leg goes and feeds the fuse box.
If nothing will work, the first thing I would do is probe the fuse box with the testlight. Probe the brake light fuse and the interior lights fuse, these stay on all the time and are fed by the battery yellow wire. If you do not have power, then you know the problem is farther back, and I would go out and check the wire at the solenoid.
If you have power at the fuse box, then turn the key to run and probe the fuse box again. This time, probe the circuits that come on with the key, like the blower fan, wipers, etc.
Thread Starter
|
Freshman User
Joined: Jun 2013
Posts: 37
Likes: 0
Im refering to key on engine off. 1 click prior to start. also called the run position
Thread
Thread Starter
Forum
Replies
Last Post
732t37
1987 - 1996 F150 & Larger F-Series Trucks
8
Dec 11, 2011 05:15 PM
Greywolf
Electrical Systems/Wiring
5
Mar 24, 2005 07:31 PM
