98 boxster cruise works when it wants

[rd400rz]

my 98 boxster cruise seems to work when it wants to ? some say the brake switch ?is there a switch under the gas pedal also ?I can feel it kick out sometimes the gas pedal when the cruise is on then it quits working my car is a manual

No switch under the gas pedal, there is one under the clutch, brake switch = brake lights, clutch switch = cruise.

[wvicary]

I think the brake light switch is dual purpose, one circuit for the brake lights and one for the cruise.

Originally Posted by wvicary

I think the brake light switch is dual purpose, one circuit for the brake lights and one for the cruise.

you might be right since a tap on the brake should always disable the cruise. I do know there is a switch under the clutch which I had to replace to restore my cruise control.

[Quickurt]

You can check both of those switches with an ohm meter. They should both be normally closed switches, i.e. when the clutch pedal is in full up position, disconnected switch should read zero, or very low ohms, (2 to 5 ohms) and open line when pedal is depressed. Same for brake. If brake reads open line when in up position, you are on brake light circuit. If both on brake pedal switch read open line when the pedal is up, there's your culprit. If the clutch pedal switch reads open line when the pedal is up, it's your culprit.
Jiggle both repeatedly while testing, as this is an intermittent problem. Very hard to find. You'll have to duplicate the problem while you are testing. If the switch loses connection for just an instant, bam, the cruise shuts down.