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AltonD
09-02-2012, 10:30 AM
I have discovered my issue with sometimes intermittent operation of the Slick RPM sensor. Now, I need some long term help.

Ever so often, the RPM indication becomes intermittent. I always check the spade connectors I use to connect the sensor to the harness. I never find anything and it starts to work again. My thinking is that I am getting oxidation on the male/female spade connectors and when I pull them apart and reconnect, I am cleaning them.

Is there a different connector to use? I would be happy with a small D-SUB connector if there was something less than the 9-pin connector available.

Alton
AFS-3500 (non-s)

Rob Hickman
09-04-2012, 11:18 AM
What about Dielectric grease on the terminals?

Stu McCurdy
10-26-2012, 07:49 PM
Here is discussion I had with Rob about RPM fluctuations and the eventual fix.

As recounted on the phone and for the record:

After 60 hours of operation on the AFS 5500 with good engine monitor indications I started to get fluctations on the AFS tachometer of up to 200 RPM. Fluctuations were always up from the RPM shown by my PropTach on the glareshield. The engine itself was always steady as was the RPM shown on the PropTach. In tracking the source for the fluctuations, I found that they went away when I turned the ElectroAir Election Ignition off and returned with it back on. This eliminated the RPM Sender and Magneto as suspects.

I changed to new plugs with no change in the fluctuating RPM. I checked the grip on the plug wire caps, I added a resister (filter) to the RPM wire, I added a chock to the RPM wire and to the Electronic Ignition power wire, all with no effect. Finally I checked the continuity of the blue ignition wires, finding one wire with good continuity and three with none. I disassembled the ignition wire boots and caps to check continuity and found the center spiro carbon wire had minute breaks just as they exitted the blue shields where they were bent back up around over the top of the blue shields and clamped with the caps. After removing the broken spiro carbon ends and carefully rebending and clamping with new caps, I rechecked for good continuity and resistance. When the igiition boots were snapped back in place, the engine was started and there was NO MORE RPM fluctuations.

So, the breaks in the Electronic Igntion spiro carbon wires were so minute that the spark was jumping the gaps as well as the plug gaps, allowing smooth engine operation, but were allowing large electro pulses to enter the RPM sensor wire to the AFS 5500.

Just thought I would pass this along so you can point others in the right direction should they have similar indications.

Stu McCurdy