Cruise control will not de-activate when hitting brake pedal

Glad you fixed it

I has Problem like that with a 12 volt accessory panel in my coach.. First time I noticed the 12 volt compressor freezer beside me was not working. Searched, no 12 volt, went to the distribution panel, no 12 volt, pulled the cord off it that feeds it (Anderson power poles) good 12 volt on the volt meter..... BAD with a test light (A test light is a fantastic diagnostic tool) went to the other end of the wire,, ONE CONTINUOUS LENGTH OF WIRE, No brakes No junctions (Measured at the wire side of the fuse) good, Bright light,,, Found the problem about 12-18 inches down the wire, it had a bulge,, Turned out be be all copper oxide in that spot.. Did the slice and solder and seal bit and it was good.. Till just recently.. and then the junction between fuse holder lead and wire came apart when I pulled on it during testing.. Did the solder and seal bit again,,, And it's back to all good.

Solder and seal is very effective.

I finally resolved the problem. I had a pin hole in the power wire that leads into the brake switch. It drove me crazy because I had power going to the switch but when I applied the brakes the power would drop to zero. While moving the wire it broke off in my hand. Anyway the problem was a bad wire the whole time. Cruise control and brake lights all work well now. Thanks for all the help and suggestions. They steered me in the right direction. Great forum !!

Standard Cruise control looks for voltage ACROSS the brake light switch.. (See exception later).. On this type if the brake light fuse is blown, no 12 volts, if the brake lights are burned out, no 12 volts. and if the brake switch is closed (Pedal depressed normally) no 12 volts, and cruise says "Brakes on" and disengages.

IF the switch FAILS to close,, 1: Brake lights wont work, 2: Cruise won't disconnect (Turn it off to kill it).


NOW: the first cruise control I ever had had a separate switch that clamped onto the brake pedal arm.. It also had a dump valve.. Now that one worked great, Not only did it disengage but if the electronics failed for any reason it DUMPED the vacuum itself. They do not make 'em that way any more far as I know.

If it's a Dodge chassis the brake light switch has 3 pairs of contacts, only one pair is for the brake lights the other 2 pairs are for the cruise control. These switches are very cheaply made and are prone to failure. Cost is about $14, brake lights might work fine but it could be the pair of contacts that cuts out the cruise, the other pair enables the cruise.

OhhWell wrote:

DennisVR wrote:

jwoods61us wrote:

rgatijnet1 wrote:
Do your brake lights work? If not, then the problem is probably in the brake light circuit, not the cruise control.

x2

x3
Happened to me on my car. Lets just say not a good feeling.
As others have said, check to see if you have brake lights. Mine had a broken wire at the switch.

x4 with one slight addition. I don't know how relevant it is to motorhomes but on 2 of the cars I have owned, there were separate switches for brake lights and cruise control deactivation on the pedal. They were imports and older so once again, probably not relevant....

X5

It has happened to me, albeit on a car, not an RV.

Naturally you want to be very familiar with the cruise control shut off switch by your left hand.

DennisVR wrote:

jwoods61us wrote:

rgatijnet1 wrote:
Do your brake lights work? If not, then the problem is probably in the brake light circuit, not the cruise control.

x2

x3
Happened to me on my car. Lets just say not a good feeling.
As others have said, check to see if you have brake lights. Mine had a broken wire at the switch.

x4 with one slight addition. I don't know how relevant it is to motorhomes but on 2 of the cars I have owned, there were separate switches for brake lights and cruise control deactivation on the pedal. They were imports and older so once again, probably not relevant....

happened to me. the switch at the brake pedal wasn't completely plugged in or didn't quite make contact. it catches your attention quickly. ;)
bumpy

jwoods61us wrote:

rgatijnet1 wrote:
Do your brake lights work? If not, then the problem is probably in the brake light circuit, not the cruise control.

x2

x3
Happened to me on my car. Lets just say not a good feeling.
As others have said, check to see if you have brake lights. Mine had a broken wire at the switch.