Features Project Car Diaries

How to Fix a Power Seat Module Without Going Broke or Crazy

On this episode of DIY Lab, Spinelli fixes an annoying electrical problem with the Jag, with some help.

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When you own an off-warranty luxury car, the Sword of Damocles hangs over your engine compartment by a horse’s hair. Your ears perk up at every sound. Was that a tick? How about that? How about that? How about that? Nights coil into vortices of primal fear: transmission meltdown, air-suspension fault, full-on powertrain armageddon. You dream of wolves, vultures, a midterm you haven’t studied for. You imagine yourself as every person on that shotgun carousel from Saw VI

Then, while you’re waiting for the worst to happen, your power seat glitches out.

I bought my 2002 Jaguar XJR 100 sight unseen (on Bring A Trailer), had it shipped from the other side of the country, got it running and registered, then waited for the powertrain to become a mushroom cloud of atomized aluminum. When it didn’t, I relaxed for 15 minutes. On the 16th minute, my driver’s side power-seat return stopped working. I jiggled the switch in disbelief, accidentally reclining it so far that even with both arms at full stretch I struggled to reach the wheel. I’m not too proud to say I cried out at that sonofabitch in real anguish. 

Spinelli cried out at the broken seat return in real anguish., The Drive

I went to the forums for help. I needed to hear from those who’d seen The Darkness, faced it, and returned battered but alive. I needed a community with answers and secret fixes born from real torment. I turned to Jagforums.com

I followed a few threads, found a reoccurring issue others had had, and dug in. After some poking around, I figured the switch was probably okay; it was likely the module that was the problem. I pulled the seats out and swapped the driver’s side and passenger’s side modules, and the seat return sprang to life with a sneering whine. I’d bought myself some time, and my sanity returned. Temporarily.

I still had to find a fix for the module itself, whose leading edge had likely become corroded, cracked, or otherwise damaged. The seat back return circuit — the first on the board — was typically the first sign of trouble. I looked for a new module, which had a Ford part number, and was quoted between $600 and $700. I dug deeper into the forum, and found the answer inside one of the many topical threads. A forum member who’d had the same problem posted the phone number for a retired Navy electronics expert in San Diego who’d fixed his module for a flat fee. Since then the expert, Darryl, had become a secret MacGyver for other Jag owners bedeviled by janky circuit boards.

Darryl’s circuit-board handiwork., The Drive

I called Darryl at home. He told me the module cases were under-protected from the elements. A corrosive combo of moisture seeping in and the circuit board rubbing against the case had damaged countless modules. In fact, he had six of them in for repairs; mine would be the seventh. I sent my module and return postage, and in a few weeks, I had it back. Darryl even called a week later to verify his handiwork. I pledged to let him know when I got around to making the fix.

That’s what I did on this episode of The Drive‘s DIY Lab video series. I’ll have to call Darryl back and let him know how it went.