Honda Accord cruise problem

[CumminsPower98]

My dad has a '91 Accord 2. 2 that's having a cruise control problem. It won't stay activated or sometimes won't kick in at all. I tested the stoplight switch and it seemed real sensitive when using the tone on my continuity tester so I replaced it but my dad says it hasn't fixed it. I'm not really suspecting the steering wheel set switch since its a momentary type switch and does cause the dash light to come on every time its depressed (just doesn't always stay lit). The main power switch always seems to work although the light on the button doesn't light up. I haven't taken anything apart to inspect/clean yet. I'm suspecting the servo is probably the problem but have no idea how to test it. Then there is the clock spring and connectors and the speed tie into the computer and so on. I don't really know where to star.



Anyone know of any common problems in this system on an Accord? Vacuum lines are good and when I remove the main line after it has been sitting not running it releases its vacuum so there is no leak there.

 

[CumminsPower98]

Update



I pretty much ruled out all the switches today including the clock spring. I took them all apart to inspect/clean although nothing looked bad. For the main power switch I even bypassed it with a jumper. I feel the servo is probably okay as there is nothing fancy in there at all and when it does come on it works just fine. The servo has nothing more than 3 solenoids with no circuit board. It works completely randomly. I'm suspecting the control box now as I don't know what else to check. I know it could be a connector or wire too but those are less likely. I suck at tracing/testing circuits especially when it comes and goes. The previous owner replaced the speed sensor. It always seems to work or not according to the 30 mph cut off point. Anyway it looks like there are some yards selling control boxes for pretty cheap so I guess will will try it.

 

[CumminsPower98]

Changed the cruise ECU for a good $20 used one and so far it has worked every time it was tried so I'm confident its fixed. Oh what fun electronics are.