Having searched the forum, I have found that a code 52 is a "backup power supply/voltage boost fault" in my father's 95 F150 4x4. But I didn't locate a thread that dealt specifically with this code. Is this a module replacement type of thing? Dad's fix was the venerable electrical tape over the offending light, but I thought maybe there was an actual solution instead of just an ostrich's solution. Anybody got some insight into this one?

 

There should be two fuses supplying power to the Airbag Diagnostic Module. Fuse 5 and 18. At least that is what my '94 Service Manual shows, your '95 should be similar. Fuse 18 supplies voltage to other devices so I would suspect a problem with Fuse 5 or the circuit leading to the module.

 

Yep, fuse 5 it was. Thanks. Now I gotta wonder what led to it blowing. Is the backup power supply a battery or capacitor or what? Is it located in the diagnostic module? I would assume that it would need to be independent of the main electrical system since the wires could be cut in an accident. Does the module boost the voltage to fire the airbag? I've never dealt with airbags before. My '79,'92,97 F250's don't have them.

 

I do not play with them much. The airbag system should have capacitors inside to run the system for a short period of time after the battery is disconnected.

Fuse 5 supplies power to the airbag module all the time. Fuse 18 has power only when the key is in the Start or Run position. There is a third fuse that supplies power to the Airbag light.