Battery Boost Switch

[figallegro]

My chassis battery on a 2005 MA gas engine would not turn over the engine so I pressed the battery boost switch and nothing happened. In troubleshooting, found out that the chassis battery was bad and replaced it. Engine starts fine now.

It seems as though the coach batteries are not being charged on shore power. When I turn on the 12v switch in the panel above the door and check the battery condition via the LED lights that also are used for the tank levels, it indicates that the batteries are fair. When I check the digital volt indicator, it is at 12.1 volts. Previously when on shore power and pressing the led battery indicator, it showed fully charged and now it does not, only fair.

Since the battery boost switch did nothing to start the engine and the batteries are at a fair reading, could this be a defective Bi-Directional Relay or is there another way to troubleshoot? I checked the coach batteries with a load tester and they are OK and the voltage at the batteries with a meter are 12.2 volts. Any suggestions?
Tony

[TandW]

Check the battery posts and ground straps. Clean and lube connections. Good luck!!

[squeak]

when you try the switch can you here the relay click of feel it click

[siggyd]

If your batteries are original,then you are just about ready for a new set.
When the batteries read 12.1 volt,it means they are very empty----so you should go to your converter(charger) and measure the voltage out of the charger,if none,or only 12.1 volt then disconnect the minus side,then check the output again. Also check if you have 120 volt AC into the charger,check the fuses in that area.
Siggy D.
05 KSDP,330 Cat,FLXC

["007"]

With the BIRD setup the chassis battery should be charged after the house batteries are fully charged. If you have shore power the display should read all leds and 13 plus volts.
The converter may not be getting its 110 as Siggy says or is defective.

[figallegro]

Squeak; I do not hear any relay or solenoid click when I press the booster switch.

[figallegro]

Just plugged back into shore power and checked the converter. It is getting 120V and the DC output is 13.6V. The meters in cabinet above door now read full battery and 13.6V. Strange, as on shore power a few days ago, it did not seem to be charging the coach batteries and now it is working again. Is there a Newmar Gremlin at work here?

Still do not hear any relay or solenoid activating when I press the battery boost switch. How can I check to see if the battery boost switch is working since I have a fully charged chassis battery?
Tony

[RVDude]

Quote:

Originally Posted by figallegro ...DC output is 13.6V... Strange, as on shore power a few days ago, it did not seem to be charging the coach batteries and now it is working again.

Sounds a lot like the house batteries are floating off just a tad below the BIRD trigger voltage point. Read this prior posting. Consider that it might be other factors than written in the post causing the lower voltage float. Could be bad house batteries, loose connection on battery, etc., as well as inverter/charger setting.

There is also a fuse for the BIRD relay, the bigger of the two relays there (smaller is the bat boost relay). Check this fuse. When on shore power (and the house is fully "charged") pull the fuse and you should positively hear the BIRD relay open. Reinsert the fuse (there is a 30sec or so delay cycle) and the BIRD should close binding the house to the chassis. The BIRD relay might even have an extremely high pitched but very quiet whine when activated. Another way to tell if it is clamped or not.

[RVDude]

Quote:

Originally Posted by figallegro How can I check to see if the battery boost switch is working since I have a fully charged chassis battery? Tony

One way without a digital voltmeter (sometimes the difference in volts is a couple tenths so you'll need a DVM to detect) is to unplug the shore power, engine off, turn on a bunch of the interior 12v light (like all the ceiling lights) and then hit the boost button. You should see a noticeable increase in brightness of the lights. Flick it a few times, it might be a subtle change. Or use the DVM to measure the chassis and the house battery voltages, apply the boost switch and measure again. Best to do these measurements right off the boost relay (the smaller one).

If you understand how the boost relay is triggered, you can jump 12v directly to that relay actuator lugs, the small wires, and see if it closes. This will isolate the relay from the rest of the switch wiring for debugging purposes.

[TandW]

If you have a cig-liter type digital voltage meter just leave it plugged in all the time. Toggle the boost switch while ignition is on with heater blower on high. You will see a change if the booster is working. Good luck!!

["007"]

Some things not covered in this thread your shore power cord goes into the black transfer switch in electrical bay. The screw connection with stranded wire will flatten out and cause a loose wire connection. With all power off remove the plate and check all the connections in the switch. You will fine the shore power cable, two #20 gage cables from load center and a cable from your Gen.
Be very careful and do not cross the circuit board. You can tape the shaft of screw driver to help. You really have to check the house battery ground cable thats attached to the frame of chassis connection should be clean and bolt tight to frame.
If you find it loose and dirty remove and clean and use a star washer under the nut and spray red battery insulating spay.
You have a #6 ground on your converter attach to frame check that also.
You may have done all this so just checking.
Just for information I have never heard the relay click either, than again I'm slightly deaf.

[figallegro]

I located the BIRD in a box in the engine compartment. Are the fuses and relays for the BIRD located inside the box? I previously checked all of the wire connection in the supply boxes to make sure they were tight and everything was still pretty well tightened.

[Mikeeg]

Take the neg. terminal of the chassis battery and hit the boost button if you get no power to your starter then your boost relay is not making the connection to your house batteries.I had the problem a few months ago the booster relay was fried and was drawing down the chassis battery.Try it and get back to me.GOOD LUCK!!!!!!!!

Booster relay from Newmar $31.00 plus shipping.

["007"]

Now that you found your BIRD take a look at the wiring of it.
If you need some more info there is fusing off the solenoid on right just below the bird that has a 5 amp fuse mounted on right battery nut of solenoid. This 5 amp fuse is in your starting circuit to turn over your starter and may feed off your boost switch. The diagram shows fuse on right my fuse was on the left of solenoid maybe they are calling it from drivers seat.
I had a problem with my battery cut off switch and battery boost because the 5 amp fuse lost a wiring clip off it, green wire with female spade clip.
The left side of fuse plugs into the fix mount attached to post on solenoid the right side of fuse pushes into a wiring clip that had pop off the spade of the fuse. The wiring spade clip is also in fuse holder. To keep the clip from coming off the fuse again I place a wire tie around the wire & fuse holder.
What caused the disconnect I do not think the wire clip was ever placed correctly into fuse holder. Had to use a real long needle nose pliers to put everything together. Not to easy with these old fingers.
Its tough to see in mine and I think its even going to be harder for you because your battery buss box is way over to the right with your Bird inside it.
Sorry I didn't jump in sooner thought you had a DP. MUST BE THAT AGE THING AGAIN.