had the scan tool on at school today to go through the codes, and while i was looking them on the computer and i heard another student yell this truck is on fire. so my teachers flew over, and i came running and found the intake air heater to be smoking and glowing red, the intake horn was red!!! we went through the circuit no damage to the wires or the circuit. I need help if anyone cAN PULL UP THE schematic for the circuit, also if anyone knows if the scanner being attached would cause this to happen? Hooked everything back again and nothing is happening, just cycles as normal... strtange thing....



codes were for high tps voltage, and somthing about the torque converter lock up switch, and also the 4x4 is on a pto cable so that was a code.... all caused by mean so yepp... although they never throught the check engine...

 

Unless the PCM took a major dump my feeling is one of the heater relays stuck closed.

 

Yeah i would check the grid heater relays. More than likely one just stuck on. I would replace both just to be on the safe side.

 

Grid heater relay stuck. Search DTR, there was a picture of one a few months ago. It got roasty!

 

Rather than pay the high dealer price for replacement relays I use a Ford starter relay. Available at most any autoparts store for around $10. The same relay was used in all Fords from the mid "50s till the '90s.

 

AHKK! AHHK!! just spit coffe all over my laptop!! you put FURD pats in your dodge!! lol just kiidin good tip infidel!!!

 

I was lucky when it happened to me, at night, the relay itself on the drivers side fenderwell melted and cancelled the fire causing process.

 

thanks for the info!! ill be sure to put new relays in this thing. we tested them with a multi meter and they were fine, but im gonna replace them anyway, and i havent had any issues since, so im gonna pick those up when i get back from college baseball camp in Florida. Thanks for the help,
john

 

I just left mine disconnected. No problems with starting in 30 degree weather here in Atlanta area.

 

haha, but i dont know how it will act in 10-20 degree up here, but its been fine for about a week now, so im thinking the scan tool made the thing smoke.

 

You hadn't accidentally commanded the intake heater test to ON while learning the scanner functions?

 

no i did not. i am very familiar with this scanner and quite capable of using it, but according to my teacher he thinks that it made the computer go into limp mode and that usually will set a base voltage to alll senors. Also i was in the transmission computer at the time. Although it is very well possible i could have messed up. After all we are all Human .... hahahahhaa
but that is quite possible gmctd..... i could have done that but i am not sure how.

 

Hehehe I'm jealous, here it is -30 so count your blessings. We'd kill for some 30 degree stuff here right now.

 

Point was not to put you on the spot, in the spotlite, but to suggest that the circuit(s) probably have no impending failure, as the event happened while connected to a scanner.

Excercise the heater several times with the scanner to verify operation B4 you start throwing parts at it, would be my advice.

 

thanks for the info and so far so good, no more issues and the system has been working for the past few weekes still. lets pray it doesnt act up anymore