Isolator Relay; Relays - Holiday Rambler Imperial 2008 Owner's Manual

ELECTRICAL SYSTEMS - CHASSIS — 9
To Start From the Rear:
When starting the motorhome from the rear,
confi rm all tools and parts are clear of the
engine and underneath the motorhome.
Turn ignition key to the ON position.
Move rocker switch on the rear start box
down to REAR.
Ensure everything is clear of rotating parts.
Hold the momentary switch to START.
After the engine starts, release the switch.
Move switch to the center OFF position,
to turn the engine off.
Check the rocker switch to confi rm it is
in the desired position.
For normal operation, place the switch
to FRONT.

Isolator Relay

This relay (located in the rear run box) isolates
the house and chassis battery systems when the
motorhome is parked. When the motorhome
is hooked to shore power or operating from
the generator, the relay closes to charge the
chassis battery. The relay also closes when the
motorhome is driven. The relay is also used in
conjunction with the "Battery Boost" switch to
engage the house batteries should the chassis
batteries be in a low state of charge.
The relay is controlled by BIRD (Bi-direction
Isolator Relay Delay) technology incorporated
into Board 6 of the Rear Run Box. Bi-directional
means the relay will close when the motorhome
is driven and when parked so both battery banks
(house and chassis) are charged whether the
motorhome is driving or when parked.
194
The BIRD technology
monitors voltage of both
battery banks so when
voltage of either battery
bank rises above 13.2
Volts DC for more than
2 seconds, the relay
will close to charge the
batteries. If voltage should
drop below 12.8 Volts
DC, the relay will open to
prevent one battery bank
from discharging the other.
This ensures the batteries
are isolated from one
another when no charge
voltage is present.

Relays

The motorhome uses various
relays to operate electrical
equipment, such as lights and
motors. If a relay needs to be
replaced, carefully record the
location of each wire and all
markings or labels.
Relays can look the same in appearance,
but differ in function. Note that on the side of
the relay is a schematic drawing identifying
87 or 87a. These current ratings differ, and
if mixed, will create problems. Ensure the
replacement relay is of the current rating to
assure proper operation.
2 00 8 I MP E R I A L
Another indicator to the type of relay is the post
or legs. Turn the relay over and look at the post.
Note differences between numbered posts:
1. The 30 post is the incoming fuse and/or
breaker power. Relay applications
supply power to the 30 post or use it
for ground. The 30 post can be used
many different ways.
060216b
Isolator Relay:
2. The 85 post is one side of the coil,
Located in Rear
tripped different ways.
Run Box in Engine
Compartment.
3. The 86 post is the opposite side of the
coil, tripped different ways.
4. The 87 posts are not common to the
30 post until the relay is tripped.
When the relay trips, both 87 posts are
common to the 30 post.
5. Using an 87a relay, the 30 post and the
87a post are common. When the coil is
tripped, the 87a post becomes inactive
and the 30 post becomes common to
the 87 post located on the outside of
the relay.
080406
080405b
30
080405c