If you have a hand pump then remove the hose that runs to the car and pull vacuum from there and watch the throttle cable and wheel to see if it moves. Also if you have a wiring diagram check the connections and you could also hot wire the pump and watch from there.

If that is all good then it will be come more complicated.

 

MORE complicated? lol Ok, I will see about getting ahold of a hand vac pump and testing the system.
Also are there any relays that I need to look at?

 

Just thought of this, and I doubt that it would, but would a bad EGR valve cause this?

 

No a bad EGR valve will not cause it.

There is a relay under the cover in the fuse box but you can check that after making sure the vacuum system is all good.

 

I found the diagram for jumping the relay to make the pump work. See pics attached.

 

So, what ever happened to the Cruise problem? Has it been fixed? My Cruise does not work. When i picked up the car it did not work at all. I found a vacumm like busted and replaced it. It worked a little for a few days, now it does not work at all.

 

I checked under the dash and everything there looks fine. I did notice that the switch at the brake pedal has an adjustment that clicks as you adjust it. It can be adjusted closer to the brake pedal so it pushes all the way in when the brake is released.

I guess I have to pull the battery and check under the tray. Who thought that was a good place for the cruise vacumme pump?

 

You don't necessarily have to take out the battery to check the connections. You should be able to see and take off the elbow without having to move anything. The pump is bolted directly to the bottom of tray, so look for the connection there.

 

Well, I finally fixed it. I looked as best I could without removing the battery but could not see any holes or breaks. I had a few holes, very large ones. Again, who's idea was it to put the cruise control unit under there?

I pulled the battery and the tray and found that both of my lines had large holes in them, hard plastic tubing. The cruise control line and the turbo boost guage line. I cut them and put a rubber vacuum line to re-connect them and now both works great. :-)

 

I gave up on mine, but you inspired me rspi, I will have another go at it.

 

Did u take a look at these instructions?
https://volvoforums.com/forum/volvo-850-16/cruise-control-not-working-turbo-boost-guage-not-working-29883/