Jayco Seneca Master Disconnect Info
I have a 2006 Jayco Seneca. It's pretty mint and has been super reliable and mostly trouble free. Most issues have been easily resolved.
I store the Moho inside in winter in an unheated but dry building. When I stored it last fall, one of the last things I did was push the Master Disconnect switch near the side man door of the coach. This should have disconnected the house or coach batteries from any loads. As they were fully charged they should have been just fine over winter, same as any other winter storage. Every spring the Moho starts right up after 7 months of storage and the coach batteries work okay.
This year the switch didn't work. The storage building was being filled up, motorhomes and trailers and boats, etc. pouring in through the door. Not a great time to be troubleshooting. I figured I was okay as everything was turned off anyways.
I went on line and "thought" I'd ordered the correct replacement relay. I ordered an Intellitec latching relay. It's used in many RV applications. I figured I'd just change it out in the spring.
This May when it came time to get the Moho, all batteries were dead. After boosting, I brought the Motor Home back home. All the batteries were completely ruined. When the voltage went down and the cold froze the batteries, they were all toast. Two big 6VDC Coach batteries in the right rear slide out compartment, plus two more 6VDC Coach batteries in a compartment under the driver's step. (The extra coach batteries were an add on that greatly extended battery endurance in our many boondocking trips). As well, the two big 12VDC batteries that supply the Chassis/engine were also dead and ruined.
$1212 CAD later, I had all new batteries and went troubleshooting the Master disconnect. The Intellitec latching relay I bought looked to be a direct replacement for the original piece that was there.
But it was not. Here's why.
The original relay in my Seneca was a KIB LR9806, according to the number stamped into the relay itself. Intellitec offered their PN 53-00066-100 latching relay as a direct replacement for the KIB LR9806. And it was.
The 2006 Jayco Seneca (and I assume all of the GM based units are alike) uses a KIB LR9806F. Yup, that little F makes a HUGE difference.
To explain why, I need to explain how the Intellitec PN 53-00066-100 and the KIB LR9806 work. These relays work by having the polarity of the voltage on their coil terminals reversed. The coil terminals are marked + positive and - negative. The switch in the coach applies power as plus and minus on the terminals and the coil moves a mechanical part inside itself that closes the relay connect and allows power to flow. Moving the coach switch to disconnect actually applies the power in reverse. (This switching of the voltage polarity is actually done by the switch itself.) This causes the relay to mechanically unlatch or open the circuit. Latching relays are used for this because once they are latched into the ON position, no more power is applied to the coils.
If you have a Coach that has a master disconnect switch that has five or six wires connected to it, then this is the the polarity reversing type of Latching relay that's in your moho. If there are only two wires coming off your switch then your unit uses what is called a "single voltage pulse latching relay".
That is the KIB LR9806F. That F means that this relay is a "single voltage pulse type latching relay".
So, how it works is: You momentarily apply 12VDC to the coil (You "pulsed" the power to the coil). That makes the relay latch to the ON position. The next time you hit the switch, you again apply 12VDC to the coil (you have not switched polarity in any way) and the relay latches to the OFF position.
If your Master Disconnect switch has only two wires coming from it, then your relay is definitely a "single voltage pulse latching relay".
I could have saved myself a lot of grief if I'd only contacted Jayco customer support first and asked for a wiring diagram. The man I spoke with was super helpful. He emailed me a complete set of all wiring diagrams for my unit. As soon as I saw the diagram, I called KIB. They pointed out the difference between the LR9806 and the LR9806F.
I ordered a replacement LR9806F from Jeff at LTD RV Parts just now. He had it in stock, knew the difference between the F and the non F, and shipped within the hour. Another great service oriented guy.
The wiring diagrams are not included in your owner's manual. I've put my treasure trove of diagrams in my manual and stored copies on my PC. May I suggest you call Jayco and give them your serial number? They will email you all the wiring diagrams for free. Even if you don't know anything about electricity, I'm betting your technician will be very happy to have them.
Oh and another interesting thing may happen to you if your relay fails. The 12VDC power for the radio in the dash of your GM Cab comes from a fuse that sits on the side of the LR9806F relay. I kid you not. When my relay failed, that 5 AMP fuse blew and the radio stopped working. Since my relay failed in the ON position, I am able to put in a new fuse and have the radio, and indeed, all the Coach 12VDC lights, etc., work just fine. But if I hit the spring loaded momentary on Master Disconnect switch, that fuse will blow and the radio goes off. The relay stays latched on, btw, so power remains on the Coach 12VDC stuff. You can clearly see why this happens if you examine the wiring diagram.
I'm certain the new correct relay will fix my problem.
Hope this helps someone else. If you have any questions, I'd be happy to try and answer them for you. And a hint to all: take pictures with your smartphone of your wiring before you disconnect anything. You'll be able to refer later.
Cheers from Newfoundland, Canada.