Bryan,

 

While the plane is on jacks, one test would be to open the dump valve (relieve all pressure) and see if the pump runs in the gear down direction, but not in the up.  This would suggest that there is some sort of "squat" switch.  If so, the most frequently used one relies on pitot-static pressure so the gear cannot be retracted until 70 KIAS is exceeded.  Some simply bypass the switch with a jumper when doing the gear checks while others may have installed a bypass switch, sometimes hidden behind the panel. 

 

Scott Krueger

 

My lancair 360 was wired professionally. When we tried to do the gear retraction tests.....nothing. We checked all the wires and made sure all were getting power where they should. Checked the breakers, switch etc. 

We overran the relay and the motor ran so we figured it was a bad relay......went to Napa and bought 2 new relays today. Installed them. Same thing....nothing.  Then we remembered that the relays were mounted to a fiberglass bulkhead and the case needed to be grounded so we attached a ground from the relay mounting base to ground bar. 

Tried the gear.....now it worked...BUT it instantly  fried the ground wire on the relay small terimal......tried to measure the ohms of the relays and no resistance....how could it be that I have 4 dead relays all brand new?

So today I installed a Master Relay.  The ones that are all metal case. Now the gear works and no wires are getting fried........but Im not happy with this result as it makes no sense why the normal relays for this job aren't working....anybody have any ideas?

Bryan