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Dynadave · 09-20-2012, 06:42 PM

Hi' I have an 05 Dynamax Isata. The solenoid that connects the house and chassis batteries stays activated all the time and gets very hot. It is located just above the solenoid that disconnectes the house batteries via a switch at the front entrance. That solenoid is working ok and does shut down the 12 volt house power, but there is still power that is activating the solenoid for the auxillary battery switch even with the 12 volt house batteries on dissconnect and the shore power also disconnected. I disconnected the chassis battery but the solenoid still had power and stayed engaged. I disconnected the wires to the auxillary battery jump switch in the cab area, still no change. I also just changed this solenoid with a new one but nothing changed. Also disconnected the inverter. Am I correct in thinking that maybe the [Parrallax] converter/charger is faulty and is sending power to the solenoid when it shouldn't? The house batteries are brand new. I think this solenoid is supposed to be activated when shore power has fully charged the house batteries and then switches on to charge the chassis battery, same with the engine charging the house batteries. The chassis battery also checks out good. I just bought the motorhome and haven't used it yet but am not aware of other problems, everything seems to work. I found this issue accidentally while cleaning things it was so hot that I couldn't hold my finger on it. I called Dynamax and they weren't much help. I've been RVing for 13 years and my experience with the dealers and rv shops has not been good. Unfortunately I am a better mechanic than electrician. Any suggestions?????

KJINTF · 09-21-2012, 09:51 AM

Hi

Many times that solenoid aka large relay is powered by two separate sources. It should be rated at 100% duty cycle 200amp and should never get hot.

One power source is from the "Boost" switch up front by the driver this power comes from the house batteries and temporally connects the house batteries to the starting battery to help start when the engine battery is low

Second from the ignition switch run position this comes from the engine battery and enables charging of the house battery from the alternator. The relay stays engaged when the switch is in the run position.

You have a problem that needs attention that relay should NEVER get hot.

YC1 · 09-21-2012, 10:54 AM

Here is a ton of information. That relay could be powered by a solar panel as well. They do get extremely hot. They are also a known failure item in that the contacts become defective and don't truly connect the batteries together well. I am considering installing a small computer fan on mine. I have actually experimented with one.

Keep in mind these diagrams are not for your rv but the setup is very similiar.

Dynadave · 09-21-2012, 09:26 PM

Appreciate your input. The solenoid stays engaged even with the chassis battery diconnected, so it is not wired to the chassis ignition key . I may install a rocker disconnect switch for that solenoid if I can't get this straightened out.
Thanks, Dynadave.

Dynadave · 09-21-2012, 09:32 PM

Thanks for your help . the Monaco diagrams make sense. My unit is a Ford chassis, I requested diagrams from Dynamax via email but I'm still waiting.
Dynadave

KIX · 09-21-2012, 09:34 PM

The solenoid contacts may be burned to the point of creating resistance which would equal heat

Dynadave · 09-22-2012, 06:01 PM

I changed the solenoid, the new one gets hot. The real problem is why is it engaged at all times? With the chassis battery disconnected by removing the ground cable, the shore power disconnected, the generator not running, and the house batteries disconnected via the battery disconnect switch the auxillary battery solenoid is still [on] engaged. It is getting it's power from the house batteries but I don't know how.
Dynadave

YC1 · 09-22-2012, 06:22 PM

Do you have a solar panel??? If not then your BIRD device is defective. I posted some schematics previously. Did anything look like your setup? Can you take pictures of the compartment and also of the compartment up front that has the fuses and relays as well.

And yes. Those solenoids get hot. They will burn your fingers. At 1.5 amps they are like a 20 Watt bulb. Heat build up is not from resistive contacts. That would be a temporary situation and there would have to be lots of current flow. I have tested these solenoids and rebuilt them on my work bench. The next time (next year) I will cycle the currently rebuilt one back in with some mods to aid in cooling and to allow more air to reach the contacts that seem to grow green stuff and become intermittent.

Dynadave · 09-24-2012, 07:25 PM

It's a bit of a relief to know that those solenoids do normally get hot. I looked at the schematics and I don't see a BIRD in my setup but I still haven't got any diagrams from Dynamax. I don't have a solar panel. Do you see any problem if I install an illuminated rocker switch [to disconnect the wire energizing the solenoid] to control this function manually other than the inconvenience?
Thanks again for your interest and help.
Dynadave

Dunner · 09-24-2012, 09:08 PM

Mine did the same thing. If even one battery is still hooked up, it will energize the solenoid. Instead of shelling out $200+ bucks for a new BCC control board, I put a switch on the yellow lead to the solenoid. I turn it on before I leave on a trip and off when I get to my destination.

YC1 · 09-25-2012, 09:28 AM

As Dunner said. Heck, you could even have it funcion from the salesmans switch circuit. I just cut my wire and put a blade connector on so I can unplug it. An inline fuseholder would work well to.

Dynadave · 09-27-2012, 08:28 PM

Looks like an illuminated switch next to the salesman switch is what I'll do. Simple and cheap fix. Thanks for your input.
Dynadave

Dynadave · 09-28-2012, 08:09 PM

I talked to a service tech @ Intellitec today [the manufacturer of my battery control center housing the auxillary battery connect solenoid] and low and behold I was told that my unit was operating normally. The solenoids do get very hot due to the continuos service. The solenoid will disengage based on voltage readings the BCC gets from the chassis and house batteries. The motorhome manufacturer and the electronic control manufacturer and not in agreement as to how this thing works but for now I guess I'll go with Intellitec's opinion that it's Ok and operating correctly.
I'm still not 100% comfortable so I may do the mannual disconnect switch add on anyway so I can turn the power draw off when not in use or connected to shore power.
Thanks to all of you for your help and thoughts.
Dynadave

YC1 · 09-28-2012, 09:05 PM

The solenoid that hooks the banks of batteries together should not be on if there is not "charging voltage". That is, something that is around 13 volts or more. If the solenoid is turned on without being on shoreline, engine running, or solar panels supplying power then something is broken. There is usually about a two minute delay before it turns on depending on the device that drives it. And as a maintenance test you should measure the voltage on each large terminal on the solenoid occassionally. If you see .5 volts difference the solenoid contacts are defunct. Since you changed the solenoid already you might want to dissassemble the old one for some confirmation that the old contacts were clean or kaput. You can dissasemble with a hammer or take it apart, clean the contacts, and put it back together to save as a spare.