In the spirit of "Let My Life Be A Lesson To Others," here's how I spent my weekend.

Friday, I was leaving the pharmacy in my 99 Ram 1500 5.2L 2WD. As I started out of the parking lot, the ABS light and Air Bag light came in - two of which I haven't. I also found that my speedometer, radio, blinkers, and wipers also didn't work (but the tripmeter kept running). By the time I got home, the Brake light came on as well.

A quick Google-Fu exercise pointed to a 98% chance of the ABS differential sensor going bad. Easy fix, right?

Sure. Until the sensor came out like this:

Rear ABS Speed Sensor, minus its housing.
My efforts to remove the sensor gently resulted in the coil housing breaking off in sensor hole. Lovely. Since the housing had snapped off just above the rubber sealing gasket and flush with the differential housing, I wrestled with the plastic piece for another twenty minutes or so. Here's what came out:




Hmmm...there's a lot of plastic missing from the bottom here. Crap. I didn't want to have to dive into the differential housing, but it looks like I don't have a choice now.

A YouTube video or two later, and here's what I found:



Side note: This was my first time opening up any differential. As such, I had neglected to clean the area surrounding the opening, which allowed the dirt and debris to land on the gears once I removed to cover. No Bueno.

I retrieved some off the parts - however, not all of the old housing was present in the casing.

Two cans of brake cleaner, a tube of RTV liquid gasket, and 2.5 quarts of 75W-90 later, it was back together.

Start the engine: ABS light on, Air Bag light on, no Brake light . Thinking it was a bad connection, I removed the harness extension that came with the new sensor and reinstalled the original connector directly to the new sensor. Nope. Nada.

I did figure out that all the multifunction switch indications that were missing while the engine was running were available with the engine off. It gave me some relief to know it wasn't a multi-component failure issue.

Went after the ABS module - removed and inspected terminals and connectors. No indications of corrosion or bad connections. Be forewarned - two Torx fasteners hold it in place. For those who have never seen their ABS module before:




Reinstalled; no change in status.

Since this 15 minute repair had eaten up pretty much my entire weekend, I decided to move on to another quick repair - ignition lock replacement. 10 minutes, I put everything back together and retest.

Truck starts. All indications clear?!?

Sometimes it's better to be lucky than good, but I wish I could understand why the indications cleared only after I performed an unrelated repair.

So, some takeaways:

- If you're truck isn't lifted above standard clearance, you'd do yourself a favor and put the rear end up on jack stands.
- If you're going to open the differential,
* Clean The Surrounding Area Prior To Removing the Cover
* Drop the spare tire and move it out of the way
- In the event that your new ABS sensor doesn't face the same direction as the old one (my old one faced driver's side), the bracket that holds the two lines will not reseat unless you readjust the holding bracket (sensor shield gets in the way). Pry the bracket open, reposition the cable to the other side of the brake line, and press the bracket closed again; then reinstall on ABS mounting stud.

Hope this helps somebody down the road. Not all problems present themselves the same way, nor do all solutions.

All the Best,
YMMV

 

Good catch! electrical system failures suck.