Does anyone have any known way to make the Series III XJ6 and XJS cruise control operational? My '87 XJ6 has a bad solenoid, and the '85 XJ6 and '86 Vanden Plas I'm fixing up don't have working cruise, either. Is there a retrofit, replacement, refit, etc. for this unreliable unit? Many thanks!

Submitted by brittik@aol.com on Wed, 09/23/2009 - 23:13

Thanks, Doug. Actually, the set speed feature of the cruise on my '87 XJ6 did cause it to accelerate at one point not long after I bought the car in '07, but that went away pretty fast. The other two cars have completely non-functioning cruise at this time. My mechanic said the system is unreliable and not worth fixing, but I think you've shed some light on that. Thanks again!

Submitted by dougdwyer1@com… on Wed, 09/23/2009 - 23:07

Here's a good write up with all you'd ever want to know:

http://www.jag-lovers.org/books/xj-s/16-Cruise.html

Used servos are cheap. You should be able to find one with good solenoids and then reseal the bellows or install a new bellows.....that'll usually fix it up for another 15 years. Also check the fuse and vacuum hose. There are other possibilities but they are less common

I installed an AudioVox cruise control on a Ser III. It works fine but the installation took several hours and the kit was about $100. Its a good alternative but truthfully I wouldn't give up on the OEM cruise control too quickly, as fixing it is usually easier and cheaper.

Cheers
DD