Easy way to test FP safety switch circuit?

[Funracer]

With the car running normally, when I touch these two nuts at the same time (the 8mm air sensor plate adjustment nut and the other one shown) with a wrench, the engine shuts off immediately. My guess its shorting out the fuel pump safety switch wiring somehow. For the wiring gurus, is this normal or do I have something else going on?

[boyt911sc]

Neil,

That is NORMAL. What you were doing was grounding part of the safety switch (insulated) to the throttle body (grounded) causing the FP relay terminal #85 to be grounded and stopping the FP.

As long as terminal #85 gets a ground contact, the FP will not RUN. This is easy to test and verify. Remove the FP relay and locate terminal #85 at the socket. This terminal (#85) and the pin @ AFS switch (driverside/cylinder 1-2-3) should have continuity all the time.

Tony

[Funracer]

Thanks Tony. Glad to hear its normal.

Wish I knew electrics like you and some of the other guys do.

Regards

[PeteKz]

Go search for Tony's threads and responses, and you'll start to grok his brain.

Further comment: That feature is for safety. If the engine stops running for some reason (fire, collision, etc.) the air plate drops to the rest position, grounding the FP relay, and shutting it off, so that it does not continue to run and pump fuel into the engine compartment.