Hello everyone. I’m in the process of trying to add cruise control to my ’91 240. I scavenged the parts from a ’91 wagon at a local bone yard and think I’m ready to proceed but have a few concerns. Here’s a link to a picture of everything I have. Does that look about right?



My concern is about how to hook up the vacuum pump. My car, not having cruise, is not pre-wired, so I removed the connection from the parts car (see picture below). I pulled the plug and traced the wire through the firewall and behind the dash. After arguing with the wiring harness for about an hour, I finally succeeded at removing what I think is all the wire I need to successfully connect and power the pump. What I wanna know is, do I have to hook this pump up as elaborately as it was on the original car, or is there an easier way? I mean, the wire came from the pump, passed through a connector and split up a few times. So, can someone help me figure out what to do? I’d really appreciate it.



Also, I checked the accelerator diaphragm (not sure of its proper name), brake pedal cut out valve and the vacuum tubing itself, and they all hold vacuum.

Thanks everybody

 

You only need the pump running when teh cruise control is engaged, so I would run a relay to the cruise pump, activated when you power the cruise up with the on switch. I am sure teh pump will have some sort of cutout when it reaches a preset vacuum, or it will be designed to run continuously.

Regards, Andrew.

 

could i have a list of these parts? i am looking to do thisto my 92 240.

Any info you have would be very helpful

Which cars i can use as a donor
How hard is the install
where are the parts
does it work well


thanks

this would be a huge help

 

To tell you the truth, I never installed it. Now, it’s been so long since I scavenged the parts, I hardly remember where and how everything goes and right now, I don’t really have the time to figure it out. Many speak of how easy it is, but I couldn’t figure out the wiring as I’m not very electrically inclined, so to speak. It seems pretty straight forward, but I never understood how to power the vacuum pump, even with the aforementioned relay advice, nor could I figure out how to tie into the harness with the speedo connection… didn’t wanna tear up my car like I did the salvage one. Even further, I’m not even sure I’m gonna keep my 240. Sorry I couldn’t help. If you find out, please post. Good luck.