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HELP you guys !! Yesterday I started my 69 F250 truck for the first time in about a month, I usually do this once a month, at least, and let the engine idle for 45 min to an hour.
The Truck ran ok no problems but when I went to turn the key off, the key switch seemed overly warm, after feeling around the back I found that the wiring to the key switch was also warm to very warm. Now I always put the battery in the truck to crank it and when the run is over I remove the battery. When I went to unhook the battery cables they were hot as fire., both of them. It wasn't an overly warm day and I've never noticed this before , not that it couldn't have happened before, I just never noticed it before yesterday.
Since I do not have the truck where it will run down the road, I just let it idle where it sits and it usually runs a little over 160 degrees on the temp guage same thing this time around,
I put the battery in , started up fine, run for an hour on idle, and turned truck off and removed the battery.
Does anyone know if there is some known issue of truck Key Switches running hot or grounding out and where would be the first place to start looking for my problem?
I would appreciate all the help I can get, Thanks guys,
HELP you guys !! Yesterday I started my 69 F250 truck for the first time in about a month, I usually do this once a month, at least, and let the engine idle for 45 min to an hour.
The Truck ran ok no problems but when I went to turn the key off, the key switch seemed overly warm, after feeling around the back I found that the wiring to the key switch was also warm to very warm. Now I always put the battery in the truck to crank it and when the run is over I remove the battery. When I went to unhook the battery cables they were hot as fire., both of them. It wasn't an overly warm day and I've never noticed this before , not that it couldn't have happened before, I just never noticed it before yesterday.
Since I do not have the truck where it will run down the road, I just let it idle where it sits and it usually runs a little over 160 degrees on the temp guage same thing this time around,
I put the battery in , started up fine, run for an hour on idle, and turned truck off and removed the battery.
Does anyone know if there is a known issue of truck Key Switches running hot or grounding out and where would be the first place to start looking for my problem?
1968/69 FoMoCo Passenger Cars & F100/750, 1969 Econoline, 1970 F100/750 & Econoline before serial number G90,001: The original ignition switch (C8AZ-11572-A) shorted out and caught fire.
In 1971, Ford introduced a new switch that replaced the POS original. This new switch originally came w/a pigtailed wire harness/plug that was spliced into the dash wiring harness.
D1AZ-11572-C .. Ignition Switch (Motorcraft SW-1054) / Available from Ford. This switch wasnotused in 1971.
The switch not longer comes with the wire/harness/plug.
Edit: See post #4 for a pic of the switch and pigtailed harness/plug.
I think I need to replace that key switch immediately. If I pull the old switch out does it have a readable number on it that I can see if it is the orignial (C8AZ-11572-A) ??
Last edited by Kurttb1; Oct 3, 2019 at 11:11 PM.
Reason: change letter
HELP you guys !! Yesterday I started my 69 F250 truck for the first time in about a month, I usually do this once a month, at least, and let the engine idle for 45 min to an hour.
So did your old switch have blade fasteners? Is that the difference between the older switch and the newer replacement? I just had to replace my 71 and found a 70 junk yard set to swap in. They both have blade connectors not pin. And yeah my pig tail looks kinda melted.
So did your old switch have blade fasteners? Is that the difference between the older switch and the newer replacement? I just had to replace my 71 and found a 70 junk yard set to swap in. They both have blade connectors not pin. And yeah my pig tail looks kinda melted.
D1AZ-11572-C switch and pigtail pictured in post #4.
...Now I always put the battery in the truck to crank it and when the run is over I remove the battery. When I went to unhook the battery cables they were hot as fire., both of them. It wasn't an overly warm day and I've never noticed this before , not that it couldn't have happened before, I just never noticed it before yesterday.
Wow Kurt, glad you ran into this on your property and not while out on the road and on fire! But the battery cable thing is worrying to me as well.
Properly sized cables in a properly working system do NOT get hot. Period. Especially not hot as fire as you were saying. So I'm thinking something else is afoot here.
Wonder though, was your battery low when you put it in this time? Or did it take a long crank to start the engine? It's possible the alternator was charging the battery at full tilt for at least some of that 45 minutes of run time, which would certainly put more heat into the cables. But this is exactly why many of us prefer to oversize the cables when we change them. Some figure that if Ford used 6ga then why not just go back. I'm a big fan of 2ga or larger, but will always put AT LEAST 4ga cables in their place. Any chance yours are the original cables? Are they in fantastic shape, or looking a little haggard these days?
At the very least you might want to remove the ends and clean them where the positive connects to the starter relay and the negative connects to the engine block. And clean the battery lugs and connection points as well, even though removing and replacing them often does tend to keep things clean looking. Never hurts to be sure.
Anyway, if the cables are looking a little bit long in the tooth, it's cheap insurance to replace them with new. Pretty sure most of our trucks can be done for under 30 bucks using 2ga pre-made cables from the local parts store, even with the better ones where they have an additional 10ga pigtail for auxiliary use.
In fact, all negative cables should have these extra wires because the main ground is not just to the engine block, but also to the body. The factory did it this way (albeit a bit differently) and so should you.
Good luck with the ignition switch. Hopefully old tired cables were the only reason for the heat, but I would take a volt-meter with you the next time you fire it up for it's monthly round and make sure that the voltage reading at the battery is no more than 15v and rarely less than 13v.
Nominal while running and charging is approx 14.5v, but a volt either way is not the end of the world and may be perfectly normal for the circumstances that moment.
Wow Kurt, glad you ran into this on your property and not while out on the road and on fire! But the battery cable thing is worrying to me as well.
Properly sized cables in a properly working system do NOT get hot. Period. Especially not hot as fire as you were saying. So I'm thinking something else is afoot here.
Wonder though, was your battery low when you put it in this time? Or did it take a long crank to start the engine? It's possible the alternator was charging the battery at full tilt for at least some of that 45 minutes of run time, which would certainly put more heat into the cables. But this is exactly why many of us prefer to oversize the cables when we change them. Some figure that if Ford used 6ga then why not just go back. I'm a big fan of 2ga or larger, but will always put AT LEAST 4ga cables in their place. Any chance yours are the original cables? Are they in fantastic shape, or looking a little haggard these days?
At the very least you might want to remove the ends and clean them where the positive connects to the starter relay and the negative connects to the engine block. And clean the battery lugs and connection points as well, even though removing and replacing them often does tend to keep things clean looking. Never hurts to be sure.
Anyway, if the cables are looking a little bit long in the tooth, it's cheap insurance to replace them with new. Pretty sure most of our trucks can be done for under 30 bucks using 2ga pre-made cables from the local parts store, even with the better ones where they have an additional 10ga pigtail for auxiliary use.
In fact, all negative cables should have these extra wires because the main ground is not just to the engine block, but also to the body. The factory did it this way (albeit a bit differently) and so should you.
Good luck with the ignition switch. Hopefully old tired cables were the only reason for the heat, but I would take a volt-meter with you the next time you fire it up for it's monthly round and make sure that the voltage reading at the battery is no more than 15v and rarely less than 13v.
Nominal while running and charging is approx 14.5v, but a volt either way is not the end of the world and may be perfectly normal for the circumstances that moment.
Paul
Hey Paul, I think I may have figured out what happened. Not sure why this didn't occur to me immediately after feeling the heat in the Key Switch and the Battery Cables. Later I was pondering why those battery cables were hot, then I realized that when I turned the truck off, I immediately tried to crank it while it was hot to see if the hot soak problem was fixed, however, when trying to crank the truck the starter would barely turn the truck over and I think I held the key on for a few seconds longer than I normally do to see if the starter would kick in higher speed. Well the starter didn't go any faster and the truck did not crank. I am curious now if the alternator is even working because the battery was like dead. Didn't think holding the starter on for that extra few seconds would run the battery down super fast??
So since I did try to restart the truck while it was hot, and held that starter on a few extra secs, I'm thinking that might be the entire problem of the key switch being hot and the battery cables burning hot. I'm not 100% sure but thinking this was the problem.
I do Thank ND for the great information about the key switch in my truck being one which is capable of shorting out and catching on fire and plan to buy that switch if the bid price don't go sky high.
Thank you very much and would like to hear you opinion on the heat in the switch, harness and the cables and if all of it could have been from trying to restart the truck.
Hey Paul, I think I may have figured out what happened. Not sure why this didn't occur to me immediately after feeling the heat in the Key Switch and the Battery Cables. Later I was pondering why those battery cables were hot, then I realized that when I turned the truck off, I immediately tried to crank it while it was hot to see if the hot soak problem was fixed, however, when trying to crank the truck the starter would barely turn the truck over and I think I held the key on for a few seconds longer than I normally do to see if the starter would kick in higher speed. Well the starter didn't go any faster and the truck did not crank.
Ok, yeah that would add additional (heavy) load to the cables and heat them up. But it's still "a thing" that needs to be addressed. You should not have a hot start issue no matter what. It's just this kind of scenario where you might be out and need the truck to start so keep on the key for awhile and that's when a weak link like an old ignition switch design would fail. But also where a failing or poorly matched battery cable would cause trouble too. Heat and electrical on an automobile is a bad thing.
However, remember one other aspect of the ignition circuit that is actually supposed to get hot. That's the resistor wire between the switch and the ignition coil. It's supposed to get hot, but it does not normally cause other wires or components to get hot. So it still sounds like you need to replace the switch, but be aware that there is always one wire that is going to be too hot to touch. They typically put it in a heat-barrier jacket/sleeve thingy to keep it from harming other adjacent wires.
Originally Posted by Kurttb1
I am curious now if the alternator is even working because the battery was like dead.
Easy to check. With the engine running you should be seeing approx. 14.5 volts at the battery terminals. Especially when all this cranking and charging is going on, you might see a smidge over 15v but it should not stay there long.
If you see anything over 13v the alternator is working, but at 13 to 13.5 it's not working hard. At 14-15 though it's doing it's thing just fine. If you see 16v or more, shut it down and fix the charging system or you could hurt the battery and maybe other things.
But you really do need to check, because being "like dead" could be another issue. Or it could just be the battery... Testing is called for here.
Originally Posted by Kurttb1
Didn't think holding the starter on for that extra few seconds would run the battery down super fast??
It's not supposed to. Either the battery was already low, the starter is really struggling for some reason, or the wiring is deficient.
All three are common issues, and all three are easy to deal with usually
Originally Posted by Kurttb1
So since I did try to restart the truck while it was hot, and held that starter on a few extra secs, I'm thinking that might be the entire problem of the key switch being hot and the battery cables burning hot. I'm not 100% sure but thinking this was the problem.
Could be. But even still it says there is a thing, or are things wrong with the starting/charging system that need to be addressed. No such thing as a hot-start issue when everything is working. Weak starter, weak battery, under-sized or failing cables, too much ignition timing advance, and probably another thing or three I'm not thinking of. All can cause the starter to drag slowly along when warm. But none area appropriate or acceptable.
If a weak battery or starter is at fault, the cables would certainly take the brunt. But if they were oversized this would likely not be a problem for them. It's just these unforseen conditions that confirm my belief that overkill is just enough when it comes to battery cable size.
And the extra cranking should not have heated up the ignition switch. There's very little load on the switch, so there is something more wrong there than just the low battery/slow cranking.
Ok, yeah that would add additional (heavy) load to the cables and heat them up. But it's still "a thing" that needs to be addressed. You should not have a hot start issue no matter what. It's just this kind of scenario where you might be out and need the truck to start so keep on the key for awhile and that's when a weak link like an old ignition switch design would fail. But also where a failing or poorly matched battery cable would cause trouble too. Heat and electrical on an automobile is a bad thing.
However, remember one other aspect of the ignition circuit that is actually supposed to get hot. That's the resistor wire between the switch and the ignition coil. It's supposed to get hot, but it does not normally cause other wires or components to get hot. So it still sounds like you need to replace the switch, but be aware that there is always one wire that is going to be too hot to touch. They typically put it in a heat-barrier jacket/sleeve thingy to keep it from harming other adjacent wires.
Easy to check. With the engine running you should be seeing approx. 14.5 volts at the battery terminals. Especially when all this cranking and charging is going on, you might see a smidge over 15v but it should not stay there long.
If you see anything over 13v the alternator is working, but at 13 to 13.5 it's not working hard. At 14-15 though it's doing it's thing just fine. If you see 16v or more, shut it down and fix the charging system or you could hurt the battery and maybe other things.
But you really do need to check, because being "like dead" could be another issue. Or it could just be the battery... Testing is called for here.
It's not supposed to. Either the battery was already low, the starter is really struggling for some reason, or the wiring is deficient.
All three are common issues, and all three are easy to deal with usually
Could be. But even still it says there is a thing, or are things wrong with the starting/charging system that need to be addressed. No such thing as a hot-start issue when everything is working. Weak starter, weak battery, under-sized or failing cables, too much ignition timing advance, and probably another thing or three I'm not thinking of. All can cause the starter to drag slowly along when warm. But none area appropriate or acceptable.
If a weak battery or starter is at fault, the cables would certainly take the brunt. But if they were oversized this would likely not be a problem for them. It's just these unforseen conditions that confirm my belief that overkill is just enough when it comes to battery cable size.
And the extra cranking should not have heated up the ignition switch. There's very little load on the switch, so there is something more wrong there than just the low battery/slow cranking.
Paul
Paul, I have headers on my truck and one of the pipes is within 1/8 inch of the starter, and very close to the starter hot wire. I have tried to use a piece of aluminum wrapped around the pipe to help mitigate the heat on the starter and the wire, but I do believe that the starter gets so hot that it doesn't work like it does when it is cold. I'm sure it gets especially hot when the truck is just sitting Idling for an hour. I had the hood up so it might have helped if I had the hood down not sure.
Things to do:
check the charging
change the key switch
upgrade the battery cables
That does make a difference. A hot starter is almost always going to be harder to turn than a cold one. Just ask any old Chevy owner with headers!
That 1/8" is pretty darn close too. I bet your heat shield did help, but it's probably not quite enough when it's that close to begin with. Not much room to work with.
So yeah, that extra heat and load that the starter is creating is definitely pushing your cables hard. All the more reason to go big here.
KEY SWITCH WIRING HOT
