Cruise Control Switch

[Hunter11]

I am sure this has been discussed before but I can't find anything on it, is there any way to have cruise control come on when you start the truck instead of having to turn it on everytime with the switch?

 

[ISBPilot]

Not sure...............

I would assume by now someone has made a box to plug into the wiring harness which would do this for you. I have heard of being able to reverse the O. D. switch this way. However, I did find out last weekend that the Cruise only works up to 85 mph. If you try to set it any higher it will slowly idle back to 85 and then hold steady there.

 

[TxDieselKid]

what I want to know is...

Is there a way to switch the crusie control to hold an RPM insted of a MPH?



AJB

 

[illflem]

On my 12 valves the cruise on button stays on all the time, last time it was turned off is when it was new. Seems like it would be easy to modify on a newer truck.



I started working on a constant rpm cruise control last summer but ran out of time, do know how to do it and that it does work. It is very easy to do. Read about it here

 

[DonS]

That thread seems to be aimed at a "constant throttle" CC, instead of constant speed.



At highway speeds, unless something was wrong with your TC or clutch - wouldn't constant RPM be the same as constant MPH???



-Don

 

[illflem]

Don, you're right rpm=mph, but it takes more fuel to go uphill, the throttle moves. The problem with the factory cruise is that it is too good. Try driving your truck in cruise barefoot, you will feel the throttle moving constantly compensating for every dip and wind gust. A diesel engine does best at a steady throttle setting, I've operated Cat equipment that has two throttle positions, idle and work. Some members here have experimented with tractor type throttle cables, set at constant throttle for long trips and have reported gains of up to 5 mpg. Problem with using a cable is you have to react very fast pushing in the throttle in an emergency stop, especially with an AT. Another easy fix I found that was good for 2-3 mpg is to restrict the vacuum line to the cruise actuator to the size of a pin hole with a drilled out piece of round steel or plastic. What this does is slow down the throttle movement for a steadier throttle, your speed may vary 3-5 mph instead of the zero of the factory cruise but you get better mpgs.