[Richard]

You might remove the cover from the HWH box. It should have a diagram printed on the inside. You may have to move one of the circuit boards out of the way, but HWH was kind enough to add red and yellow diodes to the different circuits to indicate what was going on. The only tool we don't have is the logic algorithm.

On the printer diagram you shou be able to identify which terminal is associated with the slide lock solenoid. Have a helper actuate the slide and watch the lights as the slide goes through its cycle.

As Russ said the limit switch may not be making, or the fuse could be blown for the lock solenoid, or the relay could be bad for the lock solenoid, or the relay itself could be bad. It's just going to take some detective work with a voltmeter to figure it out.

Have you downloaded the HWH 600 series manual yet from the HWH site? In addition to the diagrams printed on the cover, it will also have the wire numbers that HWH used for all the interface with the coach. Very useful when troubleshooting