Is Big boy solenoid supposed to hum?

[YC1]

Mike, on that voltage drop measurement you can still be fooled. IF the contacts are sort of working as often they do then you have the potential of the battery banks becoming full. Once they are full there will be little if any current flowing through the solenoid contacts.

That said, disconnecting power and starting the rv a couple of times in succession then turning it off and leaving headlights on for 10 minute should cause a decent imbalance in the battery banks and you can then do your test with confidence.

I know this is a bit picky but you can get fooled into thinking it is working correctly.

It is funny. If I suggested that you change a maintenance item such as a filter every few years you would not hessitate even if it is $50.



The true Big Boy relay is more pricey but many of our systems use solenoids that cost about that much. But suggesting someone change one because it Might fail falls on deaf ears. There are threads all the time on this issue and the grief they cause is untold.

Just saying. Water the batteries, clean the terminals and tighten, and change that solenoid out or at least take it apart if you can and clean and inspect the contacts.

My big boy was bad in the first year or two and not having a schematic or this forum it was a challenge even for me and I am a highly qualified certified senior electronic technician with 45 years of experience.

Ok, down off the soap box.

[CountryB]

Thanks. Good advice.

[shootist]

Yep, if a beaver is like a monaco it has an intermittent voltage to the holding coil for continuous duty. They get worse with age I think

[e4services]

No, not normal. It means the contacts on the 'Big Boy' have carbon build up.

It really wasn't a good design by Intelletec. They chatter this solenoid in and out when everything is normalized. Today, it is a solid state circuit. Google it, there is a good DIY to remove the solenoid, open it up and recond it. Otherwise replace it, it can keep you up at night!

Originally Posted by CountryB

I'm hearing a high-pitched hum coming from the Big Boy solenoid located in the rear electrical/battery box. Engine not running, plugged into shore power (20A).

Is that normal?

[Chargerman]

I purchased a new one and rebuilt the old one to have on hand as a spare the new one hummed just like the original from day one.

[twinboat]

See post #8 for the answer.

[studesrus]

Originally Posted by CountryB

I'm hearing a high-pitched hum coming from the Big Boy solenoid located in the rear electrical/battery box. Engine not running, plugged into shore power (20A).

Is that normal?

:LED Lights will hum or wine.
Stude

[DavidPP]

The discussion about the Big Boy Solenoid and its proper operation comes up quite often on the Monacoers group of which I am the Owner and one of the Moderators.
There is a lot of mis-information about the operation of the Bog Boy Solenoid and the Bird Relay. I have researched the operation of the Big Boy and the Bird Relay and the following information should help those understand the operation of the Big Boy Solenoid and Bird Relay and help in trouble shooting the system if a problem occurs.

The Big Boy System you have was installed By Monaco in most all of the Patriots, Marquis, Navigators, Executives, Dynasty, Signatures and like Monaco branded coaches. Both the BB Solenoid and the Bird Rely Circuit board are locted in the Rear Run Bay. The BB Solenoid is big and mounted almost center in the RRB and the Bird Relay Circuit Board is mounted on the right side about half way up.The board will have a Green LED on when it is operating.
When connected to shore power or with the generator running the Big Boy Solenoid(BB) will be energized. It is normal to hear a hum coming from the BB and the BB will be Hot to the touch.
When you disconnect from shore power and the generator is not running, the Green LED should be out on the Bird Relay Cicuit Board. The Big Boy Relay will drop out of the circuit when the DC voltage drops to 12.5 to 12.8 vdc when measured at the Chassis Battery side of the Big Boy Relay.

When connected to shore power or when the generator is running you should have power to the #2 pin on the eight pin connector on the right side of the board. The #1 pin is ground and the #3 pin is powered on when you turn on the Ignition
Switch. Pin #4 is from the battery boost circuit, Pin #5 is the Domestic power circuit. Pins #6 & #7 are blank. Pin #8 is a ground circuit.

The six pin connector on the top of the board powers up the relays. The left pin is Pin #1 and is ground, Pin #2 powers up the Big Boy Relay, Pins #3-4-5-6 power up the two Domestic Relays that are to the right of the Big Boy Relay.

If the BB is powered up and running correctly when on shore power or generator, you should have around 4.5 to 4.8 vdc on pin 1 of the 6 pin connector. You should also have that same voltage on pins 1, 4, 5 & 8 on the 8 pin connector.

When in Float Charge you should be seeing 12.8+ vdc on the chassis side battery post-(left side) and 13.0+ vdc on the house battery side post-(right side) on the BB Solenoid

A differential of .3 to .6 vdc between these two posts is normal.

Disconnect the six pin connector on the top of the board and the Big Boy Relay should drop out and you should be able to read the battery voltage of the chassis and coach Batteries independantly. This will also stop any drain of
the batteries when disconnected from Shore power and the genset not running.
Sorry if this may be to much information.

I hope this is helpful in understanding the operation of the BB and in diagnosing any problems.
I would also suggest a call to Mark at M&M Electronics. His phone number is; 1-419-965-3014. He is an excellent source for trouble shooting the Intelitec systems

[Chargerman]

David

Thank you very much for the detailed explanation. I was not aware that by disconnecting the six pin plug the batteries will not see a parasitic drain. Good to know.

Thanks again!!