Battery Solenoid or Switch bad?

[Larry Shew]

Not new to the links assosiated with the Winnie battery solinoid have used them to get where I am now. I have a 2000 Winnebago 32V Adventure. House battery was not being charged and Aux batt. switch at steps quit clicking. So read post and got the good solinoid from www.murcal.com trombetta 114-1211-020 bear family 12 Volt DC contactor Installed it an double checked all the wires were correct using winnies wiring diaghram with letter codes and now cannot get new house solinoid to stay energized. Everything works correctly when I physically hold in the aux. batt. switch. But the solinoid does not stay connected when I let go. It is working like the battery boost switch. where does the power come from to hold this contact in.? When switch is held in on position I only have power to LG wire or "I" side of solinoid and LH wire on "S" side only shows .5 volts? Could it be the Aux Batt switch? Thanks Larry

[John Hilley]

I haven't looked at a schematic yet, but I would think the coil would be activated by the ignition switch. You could verify whether or not the solenoid works by applying 12vdc to the coil and see if it pulls in.

[Larry Shew]

Just got a diagram from the solinod maker and it seems like I have it mounted backwards( upside down). It had no markings on it . Compared it to my factory one that has markings .the batt side and the load side are switched and the 2 small terminals I have the switch side to the ground and visa versa.
Will try again tomorrow reversing them and will leave comment.
Just bought 4 new Trogan T-105 to install in under step battery box so wanted to get this sorted out first.

[ddalski]

I just got throught diagnosing the exact same issue. I too thought I had a bad solenoid, but it turned out the chassis batteries were reading something like 6 volts - not enought to move the solenoid to the "on" position (even though the coach started and ran fine. See how many volts you have on the incoming 12V side of the disconnect coil - if less than 12V, it is probably your issue. Two new chassis batteries (I had also aready changed the coach batteries) cured mine!! The two small studs on the coil move the coil from latched to unlatched. +12V on the "I" marked side a and ground on the other small stud energises the latching (closed) action of the coil. Reverse the polarity on the small studs of the solenoid, and it opens and stays there. No current is required to maintain either position - the solenoid stays latched on or off by itself when it is working correctly. You can check to make sure the switch is working by attaching one side of a test light to ground and the other to the "I" post - it should light up when you depress the aux battery switch. Another thing is to make sure you have clean terminals on the battery connections as well as the the +12V lug distributing power to the aux relays and the starter, and also important are the the ground connections. My 2000 39' worked one heck of a lot better after I took a $3 brass wheel on a drill to all of them.

[Larry Shew]

Looks like I got a defective part. The above post pointed me in the right direction. Talk to murcal who helped me diagnose the problem and they were quick to send a new one out right away. So will respond to thread when I get it in but and pretty sure problem is solved. Thanks all for responding. These electrical gremlins can get you going sometimes ! Larry

[EngineerMike]

Larry- the Trombetta solenoid you had was not a latching type, it requires constant 12V on the small studs to keep the large contacts closed.
Latching type takes a momentary 12V on the small studs to "latch" the large contacts together, then another momentary 12V signal to unlatch. I'm not sure which type you needed.