br4x4

Hello to all, i have had no cruise control for months and have tried to fix it many times but no luck. my Snapon scanner says code P 1683. i replaced switch and clockspring and heated air soloniods , checked all wires i could see.
anyone have any ideas as to where i should look?.

1996 Dodge Ram Cummins, 4x4, 128000 miles, auto trans.

johnh

i had a '92 that kept blowing fuses,i never could find the reason so i put in a 30 amp..........end of problem

gcdodge

Cruise control is run by vacuum check your vacuum lines Does everything else work 4x4 does heat come out of all vent or just defrost vents?

br4x4

Heater works , the vents work , 4x4 works , i have great vacuum pressure.
all relays and soleniods switch when the scanner does them.

br4x4

all fuses are good checked them out again yesterday.

infidel

Unless you spent $1200 from Chrysler for DRB software for your scanner doubt if it's reading right.
The common OBD system doesn't start until '97.

Most common causes of no cruise are a rotted vacuum hose under the battery or a bad brake light switch. Since the switch is only $11 from Napa I find it easier to just swap in a new switch rather than test the old one.

br4x4

i am not getting any volts at the stop light switch. brake lights are fine.
i will replace switch today and go from there.

br4x4

I checked the servo by pulling battery and checked lines and wires, looks fine
no battery acid, no cracked lines.

br4x4

I checked the brake light switch today and it is working right. and i have the little green light on the switch on the steering wheel coming on. so what should i check next?.

infidel

If the brake light only works right sometimes just replace it for $11.

br4x4

The switch is working. what i think is the problem is the computer. P1683 says S/C power relay circuit. the computer controls the speed control. i checked
the servo wires and they are good. all vacuum lines are fine. i am not 100% sure about the computer being bad. would like to fix it myself before going to ***********.