Community Forums

Rd1 · 10-13-2020, 02:01 PM

Batt boost switch just stopped working. Have looked at other posts, but can't find any specific issues. The silver leaf shows both sides charging. The house and chassis batts also show 13+V, when under charge. The solenoid in the power compartment seems ok, though feels very hot. The F1 fuse for the boost is also fine.

I have checked the batt boost switch itself and it show 2 lines(out of 4) with 13+V when under charge. The switch does seem to function. out of the 5 connectors in the back, it does switch between 2 of them. But I have no idea which is which. and the newmar exceptional customer service does not know, doesn't have any documentation and they don't even want to check with the techs in service.

Does anyone know the mapping for the batt boost switch, or any other fuse or components I have missed? thank you.

Skip426 · 10-13-2020, 02:10 PM

Please consider adding a " signature line " so your coach info will automatically appear below your posts, as mine does below this one .

So members will have the info they need to help .
Year ? Chassis ? Newmar model #?
Right now all we know for sure is " Newmar "

twinboat · 10-13-2020, 03:27 PM

If you have an multi-meter, test the resistance across the solenoid.

All charging off, set the meter for ohms and probe both large terminals with and without pushing the boost switch. Pushing the boost should show 0 ohms.

It may be making enough contact for maintaining charging voltage ( low amps ) but will not carry boost currents ( high amps ). That could explain the heat in it too.

As a side note, if you need the boost switch often, you are letting your batteries run down to low. If storing without power, add a disconnect to remove all loads.

Rd1 · 10-13-2020, 06:28 PM

Quote:

Originally Posted by twinboat

If you have an multi-meter, test the resistance across the solenoid.

.

Thank you for the info.. when measuring the resistance across the solenoid, does the polarity of the meter matter? In one direction, nothing happens, but if I switch the meter probes, it shows 0.0, both in rest, or while charging. Red on the L side of solenoid is 0.0 and on the R side nothing. Is the solenoid supposed to be bi-directional?

Also, the boost switch itself appears to be ok, as it does open/close between 2 of the connectors that read 13+V while charge is on. The 13v reading is present regardless of the boost switch on or off. However, when I disconnect the shore power and read the 2 hot wires from the boost switch, one shows the same V as the house batt, and the other turns 0V. assuming the 2nd one is the line to the chassis Batts.

I had the solenoid issue 2 yrs ago. However, that time the chassis Batts were not getting any charge at all. Now they do get the charge. Just the wire connection from the boost switch to the chassis batt seem to be broken.

On the boost switch usage, the coach is plugged in most of the time. I use the boost switch when opening the fws, to ensure +12v supply on the chassis batts for the FWS operation. Thats how found out it was not working. it has been working fine for the last 3 yrs.

Thanks again for the help.

twinboat · 10-13-2020, 08:42 PM

All that's in the solenoud are 2 contacts and a plate that magnetically comes up and connects them.

The probes are not important in the OHM setting. It should read 0 ohms when the solenoid is closed, either way.

flyboy013 · 10-13-2020, 09:27 PM

The TM102 controls the charge bridge. When it determines that the solenoid needs to be activated, it sends a signal to a KIB relay board that’s located in the same cord reel bay. The relay closes which sends a 12V to the charge bridge solenoid for activation.

I’ve looked over the diagrams that I have for the TM102 and I cannot find an input pin that would receive a signal from the battery boost switch. Thus I don’t know where the wire coming out of the battery boost switch is going. I would expect it’s the TM102 (or the KIB relay board) but I cannot find on any drawing.

You may want to ask Silverleaf.

Rd1 · 10-14-2020, 05:22 PM

Quote:

Originally Posted by flyboy013

The TM102 controls the charge bridge. When it determines that the solenoid needs to be activated,.

Thank you for the info.. the solenoid seems to have some issues. according to SL, there has been a problem with the solenoid. apparently, the solenoid used by newmar does not have a flyback diode, hence it is prone to spikes and strange issues appear afterwards. according to SL, they have had the Gen go on/off on its own, water pump go on, the block heater go on and not be able to turn it off, etc.. it is not clear where newmar is on this yet, they may still have the old solenoid, or if they new one has been selected yet. as soon as I find a responsible adult, I'll post.

do you know if you have the White Rogers solenoid or the Ametek?

I went for s short drive and ironically, afterwards, the Batt Boost switch was operational! however, as soon as the shore power was connected, the Boost switch failed to work.

Once we get the solenoid issue sorted out, I'll look for the boost wire

flyboy013 · 10-14-2020, 08:58 PM

I do have the White Rodgers solenoid.

See post #19 of below referenced thread for my fix.

https://www.irv2.com/forums/f103/dea...ml#post5459169

hohenwald48 · 10-15-2020, 12:01 PM

I guess I don't understand what you mean by "battery boost switch not working"

I didn't see anything in the OP indicating what the problem is. How did you determine it doesn't work?

Rd1 · 10-29-2020, 08:13 AM

Quote:

Originally Posted by flyboy013

''...
I’ve looked over the diagrams that I have for the TM102 and I cannot find an input pin that would receive a signal from the battery boost switch..

fyi

Although, this may vary from model to model and year to year, you can check the wires to the small terminal on the solenoid. Likely the one closer to the wall. the boost wire go directly to the solenoid on my unit.

AnotherMike · 10-29-2020, 10:09 AM

Some solenoids have two small terminals for the connections to the coil, others have one and use the case for the second coil connection. If yours has only one then make sure the case is grounded. In my old RV the solenoid is mounted on a piece of wood... that requires a grounding wire that runs from the case mounting screw to the frame.