1959 Cruise Control Problem

[Joshua]

Good Afternoon Everyone,

I am working on my cruise control on my 1959 Cadillac.  More specifically, the "control unit" that mounts to the left cylinder head.  I cleaned the electrical components and lubricated the entire unit.  I also made a new wiring harness for it based off of the old one.  Once I had the unit installed' I thought I would first check to see if there was power going to the unit.  I turned the ignition to "on" and put the transmission selector in "Drive".  When I hooked up the "control unit", the electric motor began spinning.  The engine was not running and the cruise control "dash selector" was in the "off" position.  When I put the transmission selector into "park", the motor was still spinning.  The only way to get the motor to stop, was to disconnect the wiring harness.  I am wondering if anyone else who has cruise control, has experienced something like this?  Or if anyone has any advise as to how to fix this?

Thank you in advance,
Joshua Cross

[n2caddies]

The 59 and 60 supplement service manuals have a very in depth step by step diagnosis for the cruise using a test light. These books are a must in my opinion. The 59 was a little different as it had a cruise specific neutral safety switch. Sounds like you have the wires crossed allowing power to get to the unit without the knob being pulled. I am doing this as well on my 60 with a cruise off a 59. So far everything checks out but the solenoid isn't strong enough to hold the throttle back when engaged. Good luck
Randy

[Joshua]

Thank you for the advice  I will look it over again and see what can be done

[Joshua]

Hello everybody,

I just wanted to give an update.  I found the cause of the problem.  The electric motor inside the control unit has 3 wires.  The green one is power coming in.  The red and black wires are both ground wires depending on which way the motor is meant to spin.  The red wire had a small brake in it and was grounding against one of the sides.  Once that problem was solved, it was working just the way it should.