battery boosts

[jamescracc]

my 1999 dutch star battery boost switch does not engage the house batteries to aid the chassis batteries when starting the coach. no click at the switch or any power to the starter. any advice?

[GaryKD]

Hi jamescracc,
Welcome to posting on iRV2. Are you holding the switch or pressing and releasing it?

[wa8yxm]

There are 4 or 4 important components in that boost switch.

1: Fuse
2: Switch
3: Solenoid
4: (Optional) diode. (or Diodes)


IF you have power to the switch (use a volt meter or test lamp) then the fuse and optional diodes (if they exist) are good.

Locate the solenoid and measure across the SMALL terminals while someone presses the switch.. Should see battery voltage

Measure across the solenoid, large terminals. Should see difference in battery voltages (please use a digital meter here) then have someone press button, should go to zero or very near zero (like 0.01 volt)

[dougburi]

Quote:

Originally Posted by jamescracc my 1999 dutch star battery boost switch does not engage the house batteries to aid the chassis batteries when starting the coach. no click at the switch or any power to the starter. any advice?

The boost switch is a "press and hold" not an on and off switch.

["007"]

Your BATTERY BOOST or AUX START is part of your BIRD System wiring.
Within that wiring you have some relays that could be defective if you do not hear them operate.
Look at diagram of BIRD circuit wiring.

[lundy]

Have the same problem. Since warranty is about to expire, decided to explore why the BOOST switch would not work when CHASSIS battery was dead. What I am going to say I don't fully understand but this is what I was told. The BOOST is powered from Chassis and NOT the HOUSE side. Therefore if the Chassis is dead, you're going to have to jump to start. I know it does not make sense, but I was told that if the Boost was wired to the House side, the shore power would not charge the Chassis. Does that make any sense to anyone? I had the same problem with a diesel pusher I formerly owned. If the starting battery was dead, I had to use jumper cables from the house to the chassis -- go figure. To me, I find the Boost Switch just north of worthless! It did work once when there was not quite enough power to start but enough to get the Boost to work. My motor home sat for 6 weeks and the chassis was so dead that the dash warning lights would not even work.

[wa8yxm]

That may or may not be true on which battery powers the boost solenoid... In my previous post I listed possible problem points (Left out broken wires) one which is opitonal is "Diodes" My coach has a pair of diodes, Whichever battery has the greater state of charge... That's the one that powers the solenoid, The diodes come off both battery leads and run to the switch. So it can work both ways.. THIS is a good design in my not very humble opinion, Of course feel free to disagree with me on that.

["007"]

If you have a Newmar coach and the BIRD System, if you will look at wiring diagram when the boost button is held down the isolator relay will operate and pass the coach or house battery power through it to the plus side of the chassis battery, which will allow the starter to turn over when chassis battery can not do it.