truck keeps cranking

[79F150/F600]

Well I recently developed a problem where when I shut my truck off by the key it continually cranks (without starting). It still starts turn key and will shut off it's just that when you shut the truck off it continually cranks until I disconnect the battery. Do any of you have any ideas on what could be causing this? I think it could be the ignition switch has gone bad have any of you experienced an ignition switch acting up like this? Ohh yeah and hi to everybody as I have just joined this site.

 

[blacksnapon]

Well I recently developed a problem where when I shut my truck off by the key it continually cranks (without starting). It still starts turn key and will shut off it's just that when you shut the truck off it continually cranks until I disconnect the battery. Do any of you have any ideas on what could be causing this? I think it could be the ignition switch has gone bad have any of you experienced an ignition switch acting up like this? Ohh yeah and hi to everybody as I have just joined this site.

First off, welcome! Ignition switch, starter solenoid, and circuitry have all been known to cause this. Break out your circuit tester, and see how the power flows.

 

[1985 Ford F-150]

Is it crankin or is it dieselin (runnin backwards) after ya shut the key off.

 

[Mil1ion]

Truck pulling the small connector off the solenoid marked "S"
Now If it keeps cranking you have a bad solenoid

 

[79F150/F600]

It is cranking not dieseling, the truck has brand new starter and solenoid so I very much doubt the solenoid could be the problem. If no one else has experienced this problem before I will just tackle it tomorrow with the test light and see what I can figure of this problem.

 

[1985 Ford F-150]

Sorry I cant help ya with that one hope ya get er fixed though I know how frustratin little bugs like that are.

 

[79F150/F600]

Ohh an and I will try pulling the wire off the s terminal and see if I possibly got a defective solenoid.

 

[Mil1ion]

Just cause it is new doesn't mean it works right

use the test light to check the connector that goes to the S terminal when the key is in RUN position after you turn it there from start.

 

[TexasNomad]

I'm gonna say Ignition switch man, should like some thing may be shorted out in there and its jumping power to all the connections in the switch..

 

[Paco]

I say ignition switch too.. my 1980 f-100 did the exact same thing and that's what fixed it!

 

[expeditionman]

ignition switch or double check the solenoid...i dont how many bad ones i've gotten out of the box when i had my 78 LTD II. for some reason the 351 just ate those up....lol

 

[blackhat620]

....or is it dieselin (runnin backwards) after ya shut the key off.

FYI: Dieseling is Not "running backwards".
Dieseling is when the air-fuel mixture is fired on the compression stroke do to the excess heat in the cylinders. This occurs in gas motors when the engine overheats do to lack of coolant or the timing is off & has caused pre-detonation resulting in hot spots in the cylinders. This can happen with carbureted, mechanical fuel pump motors since fuel continues to flow as long as the engine is turning but, with fuel injected motors the fuel is shut off with the ignition switch.

 

[73F100Shortbed]

Possible to be a bad solenoid even though new. I had to go through 2 in a month before getting a good one.

 

[Mil1ion]

One thing some people don't realize with these relays.

If the relay is energized when the battery is low... the points can WELD themselves together and cause this starter run on condition once the battery is recharged.

If a battery has little power in it.. stop trying to start the engine.

 

[79F150/F600]

Well I started the truck yesterday and pulled the wire of the s terminal and it just kept cranking so seems to me that the Parts Africa I mean Advanced Auto parts strike again. I didn't put the test light to it just wanted to stop it before I caused any damage to the starter. The solenoid has a lifetime limited waranty so as soon as I can find the receipt I will go and exchange it for another new one.

 

[Mil1ion]

Because it kept cranking means the relay is pooched and the problem is not in the wiring so you didn't need to use the test light once that was verified.

 

[79F150/F600]

Good to know I pretty much was sure that was the case, I mean the wirring is pretty straight forward at that point in the truck and easy to see. I actually went as far as pulling bith small wires off the solenoid and it kept on cranking so I couldn't seee how it could of been a wiring issue anywhere else in the truck. But hey I would like to say thanks for the advice on how to trouble shoot my problem.

 

[Mil1ion]

Usually when one sees the schematic ,common sense usually kicks in.

 

[Blue Bomber]

FYI: Dieseling is Not "running backwards".
Dieseling is when the air-fuel mixture is fired on the compression stroke do to the excess heat in the cylinders. This occurs in gas motors when the engine overheats do to lack of coolant or the timing is off & has caused pre-detonation resulting in hot spots in the cylinders. This can happen with carbureted, mechanical fuel pump motors since fuel continues to flow as long as the engine is turning but, with fuel injected motors the fuel is shut off with the ignition switch.

i was told that most of the time an engine will diesel backwards and thats when most of the damage occurs.

 

[blackhat620]

i was told that most of the time an engine will diesel backwards and thats when most of the damage occurs.

No they do Not run backwards when they diesel, ever!