1980 SD Turbo Cruise will accelarate and decelerate but will not maintain a setting. Vacuum hose coming off of cruise control unit other end is loose Can not find what this should be connected to. Appreciate your help on this Thanks

 

we will also appreciate if you will give more details on what car you got

 

It is a 1980 Mercedes 300 SD 4 dr sedan Turbo diesel does the vacuum line go thru the fire wall & connect to ??? or does it connect somewhere else.

 

140 body? 1980?

i thought cruise control is electrically operated?

 

This a model 116-120 engine is a 617.950 diesel turbo 5 cyl. 300