Tom Cherry Posted December 3, 2022 Share Posted December 3, 2022 Over the years here as well as on the other forum, some of the best info and such is what did one do wrong or what happens when you don’t follow good practices. As the old adage goes, Physician….Heal Thyself. So this topic is for general information on how to avoid a Multiplex issue….as well as proving the time honored practice of proper rebooting. . FWIW…my Multiplex is a hybrid in that it has a small “brain” or IPX that controls the 3 modules and it is not the upper end CPU system. However, from many discussions and helping out folks, this situation is applicable to both. Scenario Prepping the MH for long winter storage. Exercising house batteries as well as checking SG on cells and making certain all is well. Many folks do this and get phenomenal life out of flooded cells. I did the usual and added only a smidge of electrolyte, as the Water Miser caps minimize fluid loss. Had a new Refractrometer and was comparing to the bulb style hydrometer I had been using. Both give quantitative values so you can use the SOC table. Drained or discharged the bank gradually and then recharged. The correct procedure, which I rarely use is, to let the batteries sit…then put on a light load to knock off the surface charge and then stabilize. The recommended way, per many as well as Trojan, is to pull the middle jumpers after the light load…..then measure voltage and SG. I SHOULD have disconnected or turned off the House cut off. But, I was having difficulty in getting good correlation between the two meters and got caught up in the medhanics and calibration of the new refraction meter. OK…now ready to begin, Voltage is great. 100% SOC. SG is great. Correlates to 100% SOC. Both meters are CLOSE. Batteries are maybe 3 years old (Trojan T-105). Good news. So, I put the jumpers back on and tightened the nuts. Went inside and the overhead Living/Galley switch on the Co-Pilot step console is DEAD. OK….turn on the overheads from the Multiplex panel. Then went to another Multiplex switch panel….it is DEAD. I have 8 Multiplex switch panels. 3 are totally dead. OK, you electrical “genius”….what is going on and what did you do. I had to rig a light as the modules for MPX are in a windowless bathroom. Had power to all 3. Also power to the main house fuse panel. That eliminates the 4 circuit breakers hidden behind the MPX module panel. Start scratching my head and having thoughts of a dead or partially dead MPX brain or the IPX that drives my system. So, I went outside and killed all battery switches…even though the Chassis was not the issue. I made sure the Shore breaker was off and then “cogitated” and reviewed what had happened. I had also texted my mentor and he called right after I had finished powering down. He listened very nicely to the whole gory tale, I DID neglect to tell him, unintentionally, about NOT disconnecting the house via the house Cutoff switch. KEY POINT. My House bank goes to a 300 A fuse. That fuse goes to the Inverter. There is also, on the incoming terminal of the fuse block, a cable to the house Cut Off switch. SO the Magnum does NOT go through the House cur off switch. So, his sage and calm advice….after me telling him the voltage checks I had done…..Power it back up. The jumpers were disconnected…..so, I did that first. THEN turned on the House cutoff as well as the Chassis cutoff switches. BINGO….all is well. He, like I, concluded that for SOME reason, when I connected the Jumpers before….the IPX did not boot or restart properly….so leaving it without power for a few minutes let it shut down properly and it rebooted as it should. I SHOULD also point out that my Hybrid, per M&M is the second generation. The first Hybrid MPX used the “clock” in the Intellitec EMS as a “auxiliary brain”. In the 2006 or so models that used that, you had to reboot the EMS if the MPX was flaky. Later Monaco added the IPX module and that drives my system. LATER….it hit me. There MUST have been an “arcing” or a quick voltage spike to the IPX as I put the Jumper on….and then it went away as the jumper terminal is larger than the battery stud. I reasoned that the intermittent connection had started, but shut down, for a millisecond, the boot sequence….and interrupting it messed with the IPX (brain) startup….so it was intermittent and I lost the 3 switch panels. ALL IS WELL NOW. I later texted my tech support and he concluded…..OPERATOR ERROR. BTW, his Dynasty still has the Salesman Switch hooked up. If the big CPU on his gets into a funk, he shuts down the power to the CPU via the salesman switch…..for a few minutes….then reapplies power and it boots normally. So, what I did by using the Jumper to apply and then disrupt power probably messed up the Boot sequence. All is still well. OK…..NEXT UP…. My mentor also disconnects his Big Boy during storage. It is in a barn at his house…so he can monitor from time to time. He uses a piece of copper pipe and pulls the solenoid control wire. That disengages the Big Boy and his House and Chassis are “Jumpered” so the Magnum is just maintaining. I did the same thing today except I used a short jumper between the positive on the House and Chassis. I then pulled the Big Boy “solenoid” wire from the BIRD2 Diesel module, which drives my Big Boy. As expected…CLUNK when it opened. OK….now curiosity took over…..thus…the BOGO. Since 2013 or maybe 2015, I have had an intermittent problem with my front slide hydraulic system. There were some loose connections on the Lippert motor and I have posted warnings about that. But the failure of the motor was a three strike event, First Monaco GOOFED and installed a 150 Amp CB to protect the motor. In the 2008/09 (10?) Camelots and Scepters, that should have been 80 Amps. So, when there was a high resistance connection, the CB never tripped. Second was the high resistance Lippert motor stud issues. FINALLY, after much trouble shooting, I found that the House cable to the Hydraulic pump had a 0.3-0.5 VDC voltage ddop. This was enough to increase the current….and again damage the motor. I spent days load testing and could not find the issue,. At one point, the voltage would drop severely….and that finally killed the motor. I installed a NEW hydraulic system with all new pump and valves and motor. I also corrected the CB. BUT, I would have the intermittent low voltage or drop. Driving a few miles would fix it ….or break it. So, I installed a Hydraulic Battery selector switch. I can run the slides off the House or Chassis or BOTH. I had a 200 amp fused cable in the FRB from the Chassis as well as the House, I have used the Chassis and no issues. WELL NOW I KNOW WHERE elusive 0.3-0.5 VDC drop is. The issues in finding it was catching it when it occurred. After I jumpered the batteries, I checked the voltage (Magnum is charging or maintaining). Less than 0.01 VDC difference, AS EXPECTED. So, I got curious. At the Big Boy, on the Chassis stud…13.45 VDC. On the House stud….13.12. OPPS..0.33 VDC drop or difference. NOW the fun begins. I had removed my Salesman Switch solenoid a few years back when I was trouble shooting….to get to the House Cur Off switch terminals. It is the preferred 300A Blue Seas. It tested NO VOLTAGE drop then, Today, when I did my checks, Inverter fuse (runs directly from the Battery bank) reads 13.45 VDC. Then there is a cable to the Blue Seas….and the return or the “ON” cable goes to the House Buss with all the ANL fuses, BINGO…13.13 there. So, 13.45 INTO the Switch and 13.12 OUT. That is the issue. I have a spare switch and will replace it this next spring. So there it is. Lessons learned and things NOT to do. But, I have to close with a huge thanks to Frank McElroy. As a once was an EE student and also in charge of maintenance for several large plants and did power distribution work as well as a hot rod gear head, I understand how to trouble shoot. BUT, our complex behemoths have an unusual, at least to me, structure and circuitry….and don’t get me started on the Dynasty. The skill level needed surpasses normal automotive and “factory” maintenance skills. I have learned so much working on mine and reading here and understanding and helping others troubleshoot….as well as having Frank to ask and also explain…..it is an unbelievable transformation…..and I always am learning and curious. He is a great asset. That’s it. Link to comment Share on other sites More sharing options...
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