Hi,

My cruise control was intermittent for a year. It would mostly engage but sometimes not. Now it has stopped working entirely. Before it stopped entirely it would engage for a few seconds and then stop.

I have read the notes available.

I have checked the hoses and they look good. (I could not get to the hose behind the dash.)

I sucked on the hose that goes to the servo at the T connection and the vacuum felt good.

I tried driving and using ny foot to raise the clutch and brake pedals a little to see if they we engaging the switch correctly. But I could not get the cruise control to activate.

I checked the electrical connection to the control unit.

I checked the hoses attached to the control unit and they look good.

But there are two hose connections to the bottom of the control unit and only one is connected but I could not see any hose that had fallen off. Is this how it should be?

So I am wondering what to do next to test and fix the cruise control?

Thanks,

Dean

Send me an email. I'll replay and send a four page attachment with Cruise Control diagnostic procedures.
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john

Mine did the same thing. Ended up being a bad pressure switch in the vacuum pump. Needless to say I had to replace the unit. Check the vacuum in the system especially the rubber bellow that is hooked to the throttle.
If you can get all the vacuum lines in the system to hold a vacuum then it is something electrical.
I've had to put band clamps all the hoses at the T. As the vacuum lines age they become loose on the male connectors. Thus they leak and can not hold a vacuum. No vacuum no cruise control.

Hi:

My cruise control cut out on me and it was the switch to the brake pedal that was not working. I had a spare one and everything was fine.

Thanks for the information. My first tests of lifting the clutch and brake pedal while engaging the cruise control were done at too slow a speed. Under 25mph when the cruise control does not operate by design. My mistake.

I have conducted some more tests at higher speed and it seems it might be the clutch switch not functioning properly. I will test more and look at the switch.

I get the impression I can adjust the switch on the clutch pedal?

Yep, the clutch pedal switch can be adjusted.

Not sure how much adjustment there is on the 740, but with the 240 you need to raise the clutch pedal pretty high, to have it engage the switch, so I just bypassed the clutch pedal switch, and left just the brake pedal switch.

-Ryan
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Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars