Community Forums

Fredward · 08-16-2019, 07:01 AM

The solenoid that runs all the 12 volt chassis stuff when the ignition key switch is turned on has failed. It is located up on the front run board. Currently I just bypass it with a big cable and a switch. Need to find a Napa part number or equivalent. I have found a few online that look like they would work. 200 amp, continuous duty, normally open, etc. etc. I'm too lazy to remove the failed one and check the part number because I'm currently on the road and taking it apart is too inconvenient. I'd like to get a part number so I can order it online and have it waiting for me at home when I return.
Thanks, Fred

groveb · 08-16-2019, 09:17 AM

The NAPA part number is ST85, bought mine locally for about $65

phays · 08-16-2019, 11:40 AM

Cole-Hersee 24213 is a 200 amp, insulated coil solenoid that I used to replace the ST85 that failed after that one was installed to replace the original. The 24213 has silver alloy contacts. I ordered mine from https://www.boatandrvaccessories.com...24213-solenoid

Make sure you have the diode across the coil contact going in the correct direction. Otherwise, when you turn on the ignition key you will have to wait until the diode burns out before you can activate the solenoid. Don't ask how I know.

Fredward · 08-19-2019, 06:32 AM

Thanks Pete. I know about installing them the wrong way. Been there done that. Doh!!

I recently replaced the boost relay and discovered one of those diodes was passing voltage both directions too.

Fred

Fredward · 08-19-2019, 03:44 PM

Pete,
Are you familiar with how the Boost Relay is wired? It has two diodes on it; one to keep chassis batteries from discharging through the coil and one to keep House batteries from discharging. I discovered both of them fried on my buddy's Intrigue. Then I noticed the wire leading to the oil pressure switch had it's insulation melted off. Previous owner must have hooked things up wrong; applied power or something. That Boost relay is activated by the oil pressure switch grounding the coil or the dash switch grounding the coil. Lots of messed up wiring on his coach.

Always learning - thanks again for the Cole Hersee part number. Ordered it today.
Fred

funjnt · 08-20-2019, 05:06 AM

Excellent article men. I am anticipating some relay failures as age related yes. I may just order two of these for stock. Is this the same relay we have at the rear right hand side of the coach? For me it is in the engine bay on back of the bay with fuel filters. Looks same as one up front you mentioned. I have already replaced my oil sensor and charge relay and works good now.

Fredward · 08-20-2019, 05:58 AM

It seems each model had its differences. On my 2000 Magna the relay/solenoid in the rear bay with fuel filters, coolant filter, Webasto and oil tank is the 'Boost" relay. The Cole-Hersee relay/solenoid is located in the front run bay which is up under the driver's feet. There is a third relay just like it - probably another Cole Hersee in the front electrical panel locate in the front bay. For some reason the boost relay is different. And it has way bigger diodes on it than the Cole-Hersee up front.

Fred