Hello!

1996 discovery 1 (gasoline, Left hand drive)

my cruise control works intermittently. I manually powered the vacuum pump and it was able to pull the cruise control actuator (attached to the throttle) and hold it there for a while.

pretty sure this means there are no vacuum leaks... does this mean the only other thing that could be broken is the cruise control 'ECU / module' (?). if so, is there a part number i can look up to purchase?

feel free to let me know if i'm misdiagnosing the issue, thanks a lot!

 

Here are a few things to think about. If the CC switch on the brake pedal is not adjusted properly, it could cause the CC to cut out. The speed signal comes from the RR ABS sensor, so that can cause problems. The cancel/reset button on the steering wheel could also cause problems.

All that said, I would probably check and re-flow the solders on the module circuit board first, because that is a known failure point. A magnifying glass can help look for the black rings that indicate failed solders.

Right now my CC is non op on my '94, but the '96 works fine. A while back, I bought a used replacement CC module for a D2 (including wiring connector). There are threads about how to splice that in to the D1 system. I have the feeling many used D1 CC modules on ebay don't work. It is best to get one matched to your motor HP, otherwise it can be either sluggish or surge too much.

 

D2 Hella CC ECU is the way to go. Originals failed all the time.