Ignition key switch failure?

I'm running a slick mag on the right and an EI system on the left. Only the right side is connected to the key switch. If I switch off the EI and then try to turn off the mag with the key, the engine keeps running. Ground connections are intact. Key switch or magneto problem?
Terry, CFI
RV9A N323TP

What electronic ignition is it?

Electro Air

Sorry. Forgot to mention.
Terry, CFI
RV9A N323TP

I would have to look through the electro air instructions, but The first thing to check is to make sure your key switch has a good ground and a good P-lead connection. An easy way to test is to isolate your key switch from the equation and see if that solves it. To download this, run a line from the p-lead to the cabin and bare the end. Start the engine and turn off the electro air. This should leave you running on just the mag. Touch the bare end of the wire to ground and see if the engine quits. If so, then I would suspect a bad key switch or a bad p-lead or ground wire to/from it. If it doesn't quit, then I would suspect the wiring to the electro air.

terrykohler said:

I'm running a slick mag on the right and an EI system on the left. Only the right side is connected to the key switch. If I switch off the EI and then try to turn off the mag with the key, the engine keeps running. Ground connections are intact. Key switch or magneto problem?
Terry, CFI
RV9A N323TP

Click to expand...

Never seen a mag cause this, pull the P lead off the mag and check for '0' ohms at the P lead wire with the mag switch off.

Ignition switch

Check the inside of the ignition switch. When I did a live mag check, my engine kept running. Took the ignition switch apart, cleaned and lube. Problem solved. Watch for small springs and balls.

Just the Kind of Feedback I Was Looking For...

Jesse, Walt, and Al:
Thanks guys. Will make my way out to the hangar this week and run these checks. Didn't realize that I could fix the switch, if that turns out to be the problem.
By the way, the ElectroAir has been a solid system and the engine is still running strong with over 900 hours. Just need to make certain that the ignition is not hot when it's sitting on the ramp.
Terry, CFI
RV9A N323TP

Fixed - Final Report

Did the continuity checks (good) and even bought and installed a new ignition key assembly. No joy. Was REALLY frustrated by Saturday night when fellow RVer and hangar neighbor/DAR Ted Gauthier suggested he'd get in touch with A&P Ron Cooper, who helped to develop and test the ElectroAir system. Cooper called me at home that evening and we arranged to meet at his grass strip in Fowlerville, Michigan on Sunday.
Ted joined me with his RV6 for the trip, and we arrived at the 1900 foot strip at 1000 hours. I pulled the cowl off 3TP and slid under the IP as Cooper started calling out wires to trace. We quickly ran into a problem as his diagram didn't match with the wiring coming out of the controller installed behind my brake pedals. Ron made a cell call to Mike at ElectroAir (remember, this is Sunday morning) and he talked us thru the bundle as he was driving thru downtown Chicago. In the end, we found that the original installation (done by another A&P) had placed an in-line switch on the spark advance lead rather than the power module lead. That also explained why I'd get an RPM drop during mag check with the switch in the off position.
New switch, plug the old hole (by this time Ted was under the IP, as my back was starting to act up). Meantime, Cooper is going over my engine installation, has replaced a couple of clamps he didn't like, and has painted the back side of my prop - all in under 3 hours. He also pointed out the need for an induction leak test and the probable replacement of a couple of gaskets. Did I mention that Ron does all of this work from a wheel chair!
N323TP is now running (and stopping) as it's supposed to. After weeks of fighting this problem, I once again get bailed out by my friends. What a great weekend.
Terry, CFI
RV9A N323TP