How Does the Motorhome Start Solenoid Differ from the Ignition Solenoid

GUEST POST FROM JOHN DAVIS OF JDRV SERVICES, LaPine, OR

LET'S TALK MOTORHOME SOLENOIDS.
Yes all the Diesel pusher coaches have ignition solenoids (relay).

The purpose of the ignition solenoid is to supply a continuous uninterrupted 12 volt source for the dash systems. This is what is being referred to as a continuous duty solenoid. Unfortunately most all coach manufacturers used a low amp solenoid and the result is earlier than usual failure.

We need to not confuse this with the start solenoid.

The start solenoid is a similar solenoid installed in the rear of the coach. It supplies dedicated direct 12 volt to the starter solenoid that is mounted on the starter itself when the key is turned to the start position. We have found on many of the 2008 Intrigue and Magnas that this start solenoid was no longer used causing a chattering of the starter when engaged.

It is a simple install to add this solenoid to these coaches and solves the chatter issue.

Basically the purpose of these solenoids is to insure a reliable 12 volt power source to the components due to the long runs of wire that are involved in getting power from one end of the coach to the other.