ignition wiring questions
Thread Starter
|
Senior User
Joined: Nov 2012
Posts: 254
Likes: 1
ignition wiring questions
well a year ago I knew the answer, but this old gray head is spinning on the wiring failure under my dash. I isolated my initial problem to the old wiring at the switch. I found a cracked wire and replaced it. BUT
Now the truck starts but as the switch goes to the run position- it shuts off. A new problem.
I think this would be the wire from the starter solenoid - position#2 (The small post nearest the battery) to "where" on the rear of the ignition switch -- Is the question.
The Acc, the Bat, or the center post. (The Ign has the pink resistor wire - so that's out)
(Note-The wire that was cracked went to the Acc - however this may be another new problem from messing with the old wires.)
I've checked the wiring diagrams, but the wires all have been changed and new colors added over the years, and my diagrams show only the termination at the rear of the switch.
Guess I'm just frustrated with wiring and need an answer from someone that I could understand Thanks
Now the truck starts but as the switch goes to the run position- it shuts off. A new problem.
I think this would be the wire from the starter solenoid - position#2 (The small post nearest the battery) to "where" on the rear of the ignition switch -- Is the question.
The Acc, the Bat, or the center post. (The Ign has the pink resistor wire - so that's out)
(Note-The wire that was cracked went to the Acc - however this may be another new problem from messing with the old wires.)
I've checked the wiring diagrams, but the wires all have been changed and new colors added over the years, and my diagrams show only the termination at the rear of the switch.
Guess I'm just frustrated with wiring and need an answer from someone that I could understand Thanks
Tuned
Joined: Jun 2015
Posts: 298
Likes: 3
I think you're referring to the "i" terminal on the starter relay. That wire doesn't go back to the ignition switch. It joins up with the wire going to the coil +, after the resistor portion. It's purpose is to send a full 12V to the coil while starting. If the engine fires while starting, that wire is doing its job. I would guess that your problem is somewhere along that pink resistor wire. Sounds like the coil is not getting power while in the run position. To check this, put the key in the run position but don't start the engine. Now check the coil +. You should have around 6V. If not, there is probably a problem somewhere along that pink resistor wire.
Thread Starter
|
Senior User
Joined: Nov 2012
Posts: 254
Likes: 1
Thanks for the help inline. I isolated the resistor wire and the coil is not getting power in the run position. In fact the power is not at the ign lug when the key is in the run position.
Note: (Power is at the "Bat" Lug in both the key On key Off position.)
(power is at the center bolt and the "Bat" lugs in the key On position)
There is no power at either lug - "IGN" or "ACC" in key Run or OFF position
Does this mean the ignition switch is defective?
I replaced this switch about a year ago so This was the last thing I was looking for. Wiring is original, fragile, and seriously modified by PO.
Scott
Note: (Power is at the "Bat" Lug in both the key On key Off position.)
(power is at the center bolt and the "Bat" lugs in the key On position)
There is no power at either lug - "IGN" or "ACC" in key Run or OFF position
Does this mean the ignition switch is defective?
I replaced this switch about a year ago so This was the last thing I was looking for. Wiring is original, fragile, and seriously modified by PO.
Scott
Tuned
Joined: Jun 2015
Posts: 298
Likes: 3
I'm not sure what switch you're using, but if you're sure about which terminals are which on it, then it probably is defective. No power at the Ign lug would definitely cause your starting problem.
I think I'm using a Duracraft switch, and it's been fine for about a year. But I've heard suggestions that it doesn't last long, and that the Motorcraft switch is better.
I think I'm using a Duracraft switch, and it's been fine for about a year. But I've heard suggestions that it doesn't last long, and that the Motorcraft switch is better.
Laughing Gas
Joined: Apr 2001
Posts: 1,191
Likes: 4
From: West Union, OH USA
same here
My 66 had a 67-72 switch and a hot wire from batt to coil... I installed a used switch and still have to use the hot wire. I'm not sure how to fix the situation. Mine isn't road worthy yet...
Thread Starter
|
Senior User
Joined: Nov 2012
Posts: 254
Likes: 1
thanks all for the help, it was the ignition switch, the only new part on the truck.
may be premature, I have yet to get that %&###% bezel on yet and have to push around those old wires. I've cut spring, swore, did all the right things except have three hands. Have to wait for a third hand I guess.
may be premature, I have yet to get that %&###% bezel on yet and have to push around those old wires. I've cut spring, swore, did all the right things except have three hands. Have to wait for a third hand I guess.
Senior User
Joined: Mar 2007
Posts: 481
Likes: 0
From: Deep River, CT.
No doubt it is an absolute bear to get the switch, spring, adapter and bezel back together. Your not alone on description LOL. If you have the dash gauge panel out and hanging it may be easier to reach in that way to hold the ***'y and push toward the bezel.
Trending Topics
Tuned
Joined: Jun 2015
Posts: 298
Likes: 3
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Lead Gopher
Joined: Aug 2012
Posts: 10,014
Likes: 1,565
From: Seattle
If not, here's a tool that is supposed to help with both disassembly and assembly. I have not tried one yet myself, but it looks interesting.
Ignition Bezel Tool Mustang Ford Falcon Truck Bronco Fairlane Comet Mercury | eBay
.
Ignition Bezel Tool Mustang Ford Falcon Truck Bronco Fairlane Comet Mercury | eBay
.
Thread
Thread Starter
Forum
Replies
Last Post
BigShelby
Electrical Systems/Wiring
22
Jun 15, 2007 08:33 PM
Seifferlein
1967 - 1972 F-100 & Larger F-Series Trucks
31
Mar 30, 2004 08:23 PM
tamarackstyle
1973 - 1979 F-100 & Larger F-Series Trucks
2
Mar 26, 2004 11:37 AM
77_F150_4x4
1973 - 1979 F-100 & Larger F-Series Trucks
10
Jan 4, 2001 03:00 PM