1989 Toyota Supra Automatic Cruise Control

ED WEIDENHAMER

MEMBER
1989 TOYOTA SUPRA
6 CYL
2WD
MANUAL
120 MILES

My cruise control works only when the ambient temperature is below 40 degree F. (?) The select switch (marked "Main") will only actuate when the temp is as stated. If the temp is higher it won't allow me to set a speed. I can't find a repair manual to direct me to what might be the possible reason. The "main" switch is located on the left side of the steering wheel and the "set speed, coast and cancel" switches are located on the right side. When it works, it works okay, but only when its cool enough. Weird, huh? I don't have a picture

1 Reply

KHLOW2008

MECHANIC
41,815 POSTS

Hi Ed Weidenhamer,

You mean the main switch would only operate at below 40 degrees?

That means power is not supplied to the switch thus no operation of the system.

It most probably is a wire connection problem, higher temp = higher resistance so power supply is affected.

Hope I guessed correctly.

Test for power supply to main switch.