RPM Indication Electrical Gremlins

[nucleus]

Went to go fly the other day and I had no RPM indication. Got out to the hanger today to do some troubleshooting. Traced the tach output from the pmag to the EIS, all the connections were solid, no resistance.

It was bit of a pain on the the EIS side because the wiring doesn't have enough slack to just pull the unit out and then remove connectors, you have to remove the connectors in situ. With those stupid slotted screws on those connectors I ended up under the panel. Did Bill Gates specify slotted screws on these computer connectors? I smell his handiwork.

While I was at it I clocked the left pmag for easier access to the connector. Found a loose sparkplug boot on #2 cylinder.

Put it all back together and did a runup, now I have RPM indication. Gremlins?

Hans