Community Forums

robertfruth · 09-25-2016, 02:20 PM

First off my rig is a 2000 40' Intrigue, on a Dynomax chassis.

It has a Charge/Boost solenoid (relay). DynoMax coaches are equipped with a charge/boost relay in place of a battery isolator. This relay connects the chassis and domestic batteries together when the engine is running so they both receive a charge. It also connects the two battery banks together when the 'battery boost' switch is operated to start your engine when the chassis batteries are low.

My house AND chassis batteries have a phantom draw that is draining both battery systems. First question, when I connect the first battery, (whether it is the house OR the chassis battery) the Charge/Boost solenoid kicks on ( your can hear it being energized). So I don't know if this is part of the phantom draw or incidental to the issues I am having. Is the solenoid normally in a closed position and then opens when energized? Or is the opposite true. As this solenoid immediately is energized, even with both house and chassis disconnect switches in the off position, could this be my phantom draw? Also, the solenoid is supposed to combine the two battery systems when a. the engine is running and the house and chassis batteries can be charged off of the engine alternator, or b. by momentarily pushing the battery boost switch in the cab so that the house batteries can provide extra amperage to the chassis battery to start the engine. The two wires running to the solenoid to active the solenoid come from the engine oil sending unit or from the switch in the cab. Neither of these wires have power to them when either the engine is running or when the combiner switch is pushed. As such there is no activity at the solenoid when these actions occur, this doesn't seem correct. The draw seems like it must be a pretty big draw as the three batteries are quite large. The solenoid is a White Rodgers. If the consensuses is that the solenoid is bad could I use the P/N 24059-08 made by Cole Hersee as a replacement solenoid. They seem to have identical ratings and the Cole Hersee is a much less expensive solenoid. Also, the batteries are only 6 months old. Any suggestions or help is greatly appreciated as disconnecting both battery banks when not using the rig on a daily basis doesn't make sense.

p.s. I hope this posting does make sense.

TR4 · 09-25-2016, 06:41 PM

Have you tried to disconect the oil pressure/boost switch side of the solinoid?
Te solinoid should be in the open (no contact) position when the motor is not running and the boost switch is not activated.
Could be a bad oil pressure sending unit or bad switch. Or a bad wire that is going to ground.

Try and disconect the sender and then the switch. Grounding the solinoid will activate it. If the solinoid activates without the ground signal, it's probably bad.

Bill

robertfruth · 09-25-2016, 07:02 PM

Thanks, I'll try that. Do you think that the oil sender and the boost switch completes a ground circuit to the solenoid? I ask, because when attaching a 12 volt test light to both wires with the engine running and/or with the boost switch activated I didn't get any voltage to the wires. Also, there is no dedicated ground wire on the solenoid. I was thinking that the solenoid got it's ground by it's mounting flange. I'm not sure if the boost switch is working or not, but I do know that I do have pressure at the oil sending unit on the dash.

TR4 · 09-25-2016, 10:56 PM

From my schematic it shows the solinoid getting constant power from both chassis and house batteries for the 12v positive trigger (small terminal). It uses the boost switch or oil pressure sending unit the supply the ground (small terminal) to activate the solinoid, connecting power between house and chassis batteries.

Try disconecting the negative side of solinoid (small terminal). Does it still click when you attach the chassis battery? You should have no continuity between the two large terminals with the battery connected and the above wire disconnected (small ground terminal going to sender and switch). Hope this makes sense.

Bill

phays · 09-26-2016, 07:05 AM

Not sure you need a new boost solenoid since the solenoid appears to be working when you connect a battery. The advice about chasing the ground side of the coil is good and I would start there.

I replaced my boost solenoid with the White Rodgers 586-902 solenoid mostly because it has the same terminal connection and mounting geometry as the original solenoid. I didn't want to try repositioning the large 12 volt supply wires that come directly from the batteries. It is substantially larger than the Cole Hersee but matched my existing solenoid.

Although I like the Cole Hersee solenoids and have used two of them as replacements on my coach, the W/R 586-902 lists the max inrush current as 600 amps and like the C/H a continuous 200 amps. C/H does not list an inrush current capability. Both have silver alloy contacts and isolated coils.

robertfruth · 09-26-2016, 08:24 PM

Well, I did check out the wires (grounds) going to the boost/combiner solenoid and found out that I do indeed have a oil pressure sending unit that is somehow grounding out the solenoid even when the engine isn't running. Also, with the oil pressure wire disconnected the battery boost switch is working properly. So for the moment I have put a toggle switch on the oil pressure sending unit so that I can allow the solenoid to connect the battery systems when the engine is running so that both battery systems are charged off of the engine alternator.

With that being said, I am still getting a spark when reconnecting the ground wires at the batteries, so I still need to trace down these phantom energy draws that are draining my batteries. But at least both batteries systems are separated from each other so that they won't both get drained down. Thanks for the suggestion.

TR4 · 09-26-2016, 08:55 PM

If you have a "salesman switch" at the front coach, that solinoid has a large draw. I bypassed mine and installed a manual battery disconect on the negative side of the house batteries.

Bill

Rsponsford · 09-27-2016, 10:41 AM

I had a boost solenoid that was bad even though I could hear the relay operating so be sure to use a multimeter to test to make sure it's functioning properly. Also, a separate issue I had some time ago was a solenoid shorted out and created a huge draw until it burned up the solenoid. I replaced all four of my solenoids 2 per boost system) with CH 200 amp continuous units and now both boost systems work as they should.

Sent from my iPad using iRV2 - RV Forum