Still have the electrical short issue

[Marks481]

This type of contactor or solenoid is in common use in golf carts etc. Napa Auto parts, McMaster-Carr on-line, or Amazon: Amazon.com: Cole Hersee (24059-BP) 12V Insulated SPST Continuous Duty Solenoid: Automotive

Bumper-
This is not a contactor. It is a solenoid-operated hydraulic valve. We are discussing replacing the coil, which can be easily replaced on the hydraulic valve;

The coil looks like this:


And goes on a solenoid valve...which IIRC looks considerably different than this:


That being said, the flyback diode might not be a bad idea, but probably isn't related to the fault that Woodland is troubleshooting.

 

[BobRip]

Put in the diode. It will protect the contacts, but in addition it will protect the coil. The high voltage generated without the diode can cause arcing in the coils which can breakdown the insulation and damage the coil. This can potentially damage the insulation on the internal wires. The coil might short or have an intermittent short, just like you had. A capacitor may work, but can cause resonance and some high voltages if chosen wrong, but it is better than nothing.