I recently replaced the starter on my 72 F-100. Ive heard that you should also replace the soloniod when you do that, so today I bought a new one and installed. The truck started right up, but would not shut off after I turned off the key. I did a quick google search on my phone (how did I deal with truck issues before I had that?) and ended up hitting the soloniod with a wrench and was then able to shut off the truck. I took the soloniod back and exchanged it, the guy said that the ignition switch could be a problem too. It wasn't very expensive, and I know the current switch is the original one, so I bought one. I unplugged the harness from the old switch and found the harness to be about half melted. All of the slots for the ignition switch prongs were there, but the middle prong had fused to the harness. I knew the harness wouldnt plug into the new switch correctly, so I put everything back as it was. I installed the new soloniod and the truck started and shut off several times no problem. I plan on hitting the salvage yard on my lunch break on Tuesday to snip another harness, but I have 3 questions:

1. IS THIS A FIRE HAZARD? As long as the switch works, can I drive the truck, or should I park it and disconnect the battery until I replace the harness?
2. If the salvage does not have a 67-72 pickup, will a harness from a 73-79 hook up the same?
3. How in the heck did this happen? Should I be worried about something else?

I honestly can not tell how long the old harness has been like that, it wasn't hot, didn't smell like melted plastic so I don't think it happened recently but I really don't know. My main concern is the fire danger, I had an old Corona catch fire one time in my younger days and that still haunts me!

Thanks in advance!

Al

 

1. Yes anything electrical can cause a fire & you have an obvious defect. Disconnect the battery.

2. Why in the world would you want 40 yr old wiring to replace 40 yr old wiring? How about either building a new or buying new? No as far as wiring goes many times they change from year to year not series to series.

3. It is 40 yrs old.

 

Thanks, I was afraid of that. I guess I thought I would have problems getting a harness before an upcoming camping trip this Thursday so I thought the salvage would be a good way just to get through the weekend. I saw that LMC has the new harness, I could probably get that shipped in time. I will check the local places too...maybe I will luck out. I HATE electrical problems!

 

Can an ignition switch cause a fire? Absolutely!

1968/69 F100/750 & 1969 Econoline, 1970 F100/750 & Econoline before serial number G90,000, 1968/69 FoMoCo Passenger Cars, 1970 Falcon & Maverick, came from the factory with a defective ignition switch: C8AZ-11572-A

The switch shorted out and caught fire! 10's of 1000's of vehicles were damaged or destroyed, some people lost their lives.

In late 1970, FoMoCo came out with a new switch kit (D1AZ-11572-C / Motorcraft SW-1054) to replace C8AZ-11572-A / Kit consists of new switch and a pigtailed wire harness/plug.

There were no Gov't mandated recalls back then. FoMoCo sent the dealers a "campaign" letter detailing the problem and the fix. It was then up to the dealers to notify the customers. Some did, some did not.

So, if you have one of these vehicles, and the ignition switch wires are not spliced for the pigtailed wire harness/plug, the original POS switch is still in place!

D1AZ-11572-C .. Switch Kit is available from Ford / MSRP: $66.40 // FTE sponsor tousleyfordparts.com price: $40.17.

NOTE: This problem does not affect 1967 F100/750's, as the switch is different (C5AZ-11572-B).

Does not affect 1970 F100/750's & Econolines from serial number G90,000, 1971/72 F100/750's & 1971/74 Econolines, as the switch (DOTZ-11572-A) is different.

 

Superb info, Bill. Stellar.

 

Wow... I just had the same exact thing last week... I had to look at the beginning of the thread to make sure it wasnt mine.



I got a new switch and solenoid from the local parts store and ordered a new PigTail (the original on broke apart trying to remove it) from LMC for about $15... Works great now...

 

Did'ja see what I typed in post 4? With a 1968, you're lucky your truck survived, cuz many did not.

 

Oh.. I saw it... You should have seen the wiring. All of the insulation was burnt off and was heavily oxidized. So it mush have happened 10+ years ago. I tried to pull the plug out of the back of the switch and I wouldn't budge. Had to take a flat head and a pair of pliers to separate them. Its a wonder it worked at all. This Thursday I have the day off and i am going to climb under the dash and see what else is crispy. I have several spools of brand new wire, connectors, heat shrink insulator and a soldering iron to take care of the problem before I (or my wife) have to make an insurance claim (Auto or Life insurance).

 

Hells bells, I was working the back parts counter while these vehicles were burning up. So I've seen almost as many fried wires as Carter has little pharter starters (liver pills).

 

Uh... Is that a Georgia reference (Jimmy Carter)?