I wrote:
blockquote
I have an irrigation system using 24V Hunter solenoid valves (hydraulic
assist). Solenoids have DC resistance of 24.5 Ohm when healthy.
/blockquote

NSM replied:
blockquote
I'd be looking at the connections, mate. Could be corrosion.
/blockquote

Possible but, in this case, I think unlikely. The solenoids are potted
in solid lumps of plastic - they are, after all, designed for a wet
environment.

I thought that corrosion/damp in the joints between the flyleads from
the solenoid to the feed cable so I cut off several inches of the
flyleads and put my meter onto clean, dry, wire.

Still read several MOhms rather than 24.5Ohms.

Thanks for your thoughts, anyway.

Cheers

Matthew Smith