fltdriver

I replaced my thermal fuse, after hooking the battery up without the clockspring fried it, about 8 months ago. Simple process, there are only a couple places that sell the fuse and it must be soldered in. I did a write up, with pictures, a while back on fixing code 51:

https://www.f150forum.com/f10/code-51-a-258113/

bscottie

• a little more checking today, FWIW, I am reading the codes by the flashes of the airbag light, I went through the following

• removed airbag, hooked up airbag monitor, get code 13 and chiming
• unhooked clockspring wiring, get code 14, no more 13
• pulled air bag monitor, thermal fuse blown and resistor burned, small plastic housing melted
• checked for shorts in wiring for crash sensors, none detected
• ordered a couple of thermal fuses (167c), not sure about the resistor, from what I have found it is OK to leave out
• will see what happens when I get fuses

fltdriver

Even being burned on the outside the resistor should still function properly, it's a very simple component that rarely goes bad.

bscottie

its toast, quite the heat on this one, has me concerned that I haven't found the root cause yet


do you know the rating of the resister? is it actually needed? the little plastic piece had contained both with both being soldered in

fltdriver

To be honest I have know clue, if you can read the numbers on it you should be able to google it, otherwise your best bet may be stealing one from a JY or atleast investigating for the #. On the other hand someone might have it accessible to check or know off hand.

fltdriver

Btw unhooking anything with the battery connected will fry the thermal fuse every time (once it's replaced) because each connection has a grounding spring that shorts the fuse anytime something is disconnected.

What I found:
13 Air Bag Module or Center or RH Frame Rail Front Air Bag Sensor Circuits Short to Ground

Possible Causes

NOTE: Circuits 617 (PK/O) and 619 (PK/W) are connected together inside the air bag diagnostic monitor . Therefore, a short to ground on any of these circuits will short all of the circuits to ground.
Low voltage at pin 11 of the air bag diagnostic monitor can be caused by:

• A short to ground within the main wiring or Circuits 614 (GY/O), 615 (GY/W), 623 (P/W), 617 (PK/O) or 619 (PK/W) causing the diagnostic voltage to drop.

• An internal short to ground within the air bag sliding contact causing the driver side air bag circuit(s) to be shorted to ground.

• An internal short to ground within the RH cowl side panel front air bag sensor and bracket causing Circuit 614 (GY/O) or 623 (P/W) to be shorted to ground.

• An internal short to ground within one or both center air bag sensor and brackets and front air bag sensor and bracket causing Circuits 617 (PK/O) and 619 (PK/W) to be shorted to ground.

• An internal short to case ground within the driver side air bag module

bscottie

@ fltdriver, thanks for the tips, using my cheapo meter the clocksprings seems to be showing higher than the listed resistance, I am going to get my better meter out and do some more checks as well as verify my initial checks with the cheap meter were positive.


I went through all the pin to pin tests and found no short, also checked the crash sensors, thought I did have an issue with the right front but after rereading I realized with the module unplugged there is a direct short to ground, just need the fuse to continue

bscottie

did a little more checking today, I put in a new thermal fuse, don't have a resister to install, haven't figured out what I need yet


first out without the clockspring or air bag module wired in got code 14


unplugged crash sensor on passenger side, code 14 gone, now it has code 13,


rechecked, hooked all pieces back up, clockspring, crash sensor, air bag module, get code 13


per pin test in manual I get a short to ground on pin 11, unplugged both sets of wires under dash to clockspring, still get short to ground


test in manual says to hook up air bag simulator tool,


is this just the sign my clockspring is bad and due to not having the circuits completed I get the fault?


any suggestions for additional test without the simulator tool?

bscottie

so after getting my better meter, the clockspring had a high resistance reading, new one from rock auto, exact part number on my existing one, get all back together and all codes cleared, got ready for the test drive, closed the hood and the code 14 can back on, I rechecked all the wiring, can't get the front right sensor to show a short but it has to be, found one to at least try at this point, will know more after it arrives

bscottie

well have just hit a dead end, get the code 14 and can not clear, have gone over all the wiring and sensors, nothing helps. right now the only thing not right is the resistor in the module hasn't been replaced, according to the manual if all checks good for troubleshooting under the code 14 it says to go to the code 51, gonna let it rest for a while and get back after it once the frustration settles, deductive reasoning tells me its in the module, if anyone has any other tips it would be appreciated.