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Boost Solenoid - Preparation for Manual Use

Yahoo Message Number: 70863
Boost Solenoid - Preparation for Manual Use

Background.

The Boost Solenoid is a constant topic in this group.
The solenoid operates under various conditions, namely every time the engine is operated no matter what the start battery voltage is or the difference is between the start and house bank (tied together after the engine starts) or when used to boost a weak start battery.
On a small engine, an ISC330, by today's standards, with 70 deg F day cranking amps jumps between 327 and 375 repeatable until the engine starts. On my coach, currents are monitored by two hall effect dc current coils ? one on the start (chassis) and one on the house battery bank.
To obtain long life, consider the following.
With voltages readouts on the start and house bank, do not use the boost solenoid for starting if the start battery is less than 11.75 vdc as the amperage on the solenoid contacts could exceed 600 amps. The solenoid contacts are rated at 200 amps continuous with an inrush of 600 amps on most coaches. If you do it under these circumstances, then consider replacing the solenoid.
Prior to using the boost rocker switch, the solenoid contacts need to be exercised to clean off the corrosion which may develop in storage or infrequent use. This is done by holding the boost switch in the On position for one second and then off for one second about ten times. Then hold in the On position until the voltage difference between the start and house bank is less than 1 vdc. If this cannot be achieved in less than 15 minutes, then consider using the solenoid but with replacement in mind.

Fred Kovol

2000 Allure 30593

Re: Boost Solenoid - Preparation for Manual Use

Reply #1 –
Yahoo Message Number: 70877
Do the boost solenoid contacts connect the house and start battery banks when the ignition is turned on, when the starter is activated, or only after the engine actually starts?
If it's closed connecting the banks every time you turn the ignition on to start or activate the starter, of course, the surges connected with starting occur every time and you have no control. I am under the impression that the boost switch is to allow equalizing the charge with the ignition in the off position if the start battery was inadequate and that the switch should be in the off position when actually starting (cranking) presumably to avoid the surges across the solenoid relay contacts described even if you have used it to "boost" the start battery..

Jim M

'02 Intrigue @11410 ISL 400

Re: Boost Solenoid - Preparation for Manual Use

Reply #2 –
Yahoo Message Number: 70878

The Boost solenoid comes on when the 'boost' switch is pressed or when the oil pressure exceeds about 10#. The oil pressure switch is to charge the house batteries when the engine is running.

Dave

aka Billy Byte (trusty hound)
2000 Allure #30443

Re: Boost Solenoid - Preparation for Manual Use

Reply #3 –
Yahoo Message Number: 70887
Good info Fred. Where is this solenoid typically located? Thanks.

Larry, 03 Allure, 30856

Re: Boost Solenoid - Preparation for Manual Use

Reply #4 –
Yahoo Message Number: 70897
I have been trying to locate a boot solenoid and was wondering if anyone had a good source.

BrianO'Day

06 Inspire #51565
Portland, Oregon

Re: Boost Solenoid - Preparation for Manual Use

Reply #5 –
Yahoo Message Number: 70898
Amazon has this one.

PAC PAC-500 500-Amp Battery Isolator Relay

Jack Allure40 30076