[hharney]

Originally Posted by AV8ing

We've got a D Model (engine driven hydraulic pump) and the gear doors are not closing on gear extension.

Ground test: battery off, hand pumps gear doors open - battery switch on, hand pumps doors closed, checks ok.

Any ideas on troubleshooting this ?

Thanks!

Sounds like it's in the microswitch loop. It's daisy chained so any open connection will not allow the doors to close. Check all the micro switches and inspect each connector very carefully. A loose connection on a terminal or broken wire are sometimes hard to see.