Hi, I know there are some pretty knowledgeable people on here, so I figure I'll get an answer or two. I've got a 98 Mountaineer, 5.0, AWD. Has 176K on it and still runs fine, recently replaced the tranfer case, but other than that it's pretty much the way it came out of the factory. Here's my problem: Had a Airbag light come on flashing a "12" code. So I replaced the fuse in the power distribution box, now I get a code"52". I guess that's because I replaced the fuse without disconnecting the battery ? So I'll have to get the dealer to reset the light for me, or wait the 256 starts to get it to go away. But at the same time the airbag light went on, my A/C quit working too. I've checked the freon level and it's fine. The A/C clutch kicks in runs for a second, then kicks off repeats forever. Everyonce in awhile it never even kicks in.

Is there any connection between the two systems that might cause this...? Or is it just a coincidence that they both went at the same time? I'm kinda hoping that once I get the airbag light reset, the a/c will go back to working? I know...what are the odds....I can hope can't I ? Any insight would be quite helpful...thanks in advance....

 

I don't see how the problems could be related. HOw did you confirm the freon was ok? If you are sure the freon is good, check the low pressure switch.

 

I have a recharge kit that has a gauge on it. It show the level to he high on the "filled" scale, almost into the "alert" scale.

I disconnected the harness from the low pressure switch and jumped the leads. started the truck and turned the a/c to max....the clutch kicked in and continued to run until I turned off the ignition. Am I correct in assuming the the switch is therefore the problem....?

And just to bring things up to date, I did the blend door fix a couple years ago and haven't had any problems with it since.

Thanks for the help.

 

i would guess you are a bottle low on gas (R134). with the gauge on the low side, you should have about 120 psi, motor off. start the motor and compressor. gauge will go down to about 40 psi. rev engine to 1500 rmp like going down the road. compressor will kick out if pressure goes below 25 psi. my guess, you just need a shot of gas to get the pressure up 10 more pounds.

 

1.Your two problems are totally unrelated.
2.The dealer cannot "reset" the air bag light nor will it go away after 256 or 10,000 starts. It will not go away until the fault is repaired. Once the fault is repaired the lamp will go out.

Are you still getting the LFC 52? Or any other codes?


From the FORD manual:
Pinpoint Test A: LFC 12/52/DTC B1867 — Lost Battery Feed or Low Battery Feed Voltage

Normal Operation

The air bag diagnostic monitor (14B056) measures the voltage at Pin C232-14, Circuit 937 (R/W). The voltage at Pin C232-14 should be equal to battery voltage. If the voltage at Pin C232-14 drops below 8 volts, the air bag diagnostic monitor will flash a lamp fault code (LFC) 12 on the air bag indicator. If the voltage at Pin C232-14 drops below 5 volts, the air bag diagnostic monitor will store diagnostic trouble code (DTC) B1867 in its memory. Should the loss of battery voltage at Pin C232-14 be intermittent or repaired, the air bag diagnostic monitor will flash an LFC 52 (or higher priority code if one exists) on the next ignition switch cycle.

Possible Causes

WARNING: Do not under any circumstances substitute another fuse value for the power distribution box Mini Fuse 5 (10 A). Any fuse other than 10 A can cause disarming failure and can result in danger to the occupants of the vehicle. Do not attempt to replace the power distribution box Mini Fuse 5 (10 A) unless the battery ground cable has been disconnected and the backup power supply energy has been depleted. To deplete the backup power supply energy, disconnect the battery ground cable and wait one minute. Be sure to disconnect auxiliary batteries and power supplies (if so equipped).

NOTE: If a short to ground exists on any of the air bag module Circuits 607 (LB/O), 614 (GY/O), 615 (GY/W), or 616 (PK/BK), leading to a lamp fault code (LFC) 13 or 53 and a diagnostic trouble code (DTC) B1913; or, similarly, a short to ground exists on any of the air bag sensor circuits 617 (PK/O), 619 (PK/W), 624 (Y/W), or 625 (Y/LG), leading to an LFC 14 or 54 and DTC B1914, the air bag diagnostic monitor will activate an internal solid state switch at Pin C232-13 of the air bag diagnostic monitor. The activation of this switch shorts Circuit 937 (R/W) to ground, causing the power distribution box Mini Fuse 5 (10 A) to open, thus disarming the air bag supplemental restraint system (SRS) and preventing inadvertent air bag deployment.

Lost battery feed voltage at Pin C232-14, Circuit 937 (R/W) can be caused by:

an open in Circuit 937 (R/W).
an open in the power distribution box Mini Fuse 5 (10 A).
an open in the circuits feeding the power distribution box Mini Fuse 5 (10 A).
a short to ground on Circuit 937 (R/W).
Low battery feed voltage at Pin C232-14, Circuit 937 (R/W), can be caused by:

A concern in the charging system causing battery voltage to drop below 8 volts.
After the air bag diagnostic monitor has disarmed the air bag system, it will not be enabled to disarm again until the appropriate condition (DTC B1913 or B1914) has been repaired and cleared by performing the appropriate pinpoint tests.

 

Thanks for the replies on the airbag light problem. I do have the factory service manual on disk and was aware of the info that NCRANCHERO posted.... Thanks again....The rerason I was getting the 52 code is that I replaced the mini fuse without disconnecting the battery, because I didn't read the whole instruction first, my bad. usually, you find a blown fuse, you replace it with a good one. if it doesn't blow immediately, that usually indicates that you fixed the problem. I went to a local repair shop and had the mechanic hook up his star tester to it. he has all the different modules for his tester and was able to call up the error codes, which indicated a short somewhere, which is what caused the initial fuse blowout. He then cleared all the codes and like a miracle, no more airbag lights flashing. It does the self diagnosis and then turns itself off. Just like it's supposed to. Somewhere there must be either a loose connection or possibly a bare wire, and the entire scenero could play itself out again, but for now it's working fine.

Back to the a/c, I replaced the low pressure switch, and hooked up the recharge kit again. it still showed that the system was"filled"....with the engine running, it would increase the pressue until it got to about 50 psi, then it would drop to around 25 or so and repeat......still no cooling though. I did manage to get a little more freo into the system, but not enough to make any change in how it's acting. I'm taking it to a repair shop in the morning and the guy's going to diagnose it for me. He was also think low pressure switch......maybe it's the high pressure switch, since it never really build up any high pressures....?? I'll post the results here tomorrow