Monaco CAYMAN 2007, Manual

Page: 164 / 226

ELECTRICAL SYSTEMS-CHASSIS - 9
160
2007 CAYMAN
Battery Boost Solenoid
The battery boost
solenoid is located in the
battery compartment.
A dash-mounted
momentary switch is
added to provide a boost
for the engine batteries
from the house batteries
in case the chassis
batteries are weak and
will not crank the engine.
When traveling, the solenoid is engaged,
charging both the house and chassis batteries at
the same rate.
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 if the relay
is 87 or 87a relay. These current ratings differ,
and if mixed, will create problems. Ensure the
replacement relay is of the current rating to
assure proper operation.
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. Some relay applications
supply power to the 30 post. Some use
it for ground. The 30 post can be used
many different ways.
2. The 85 post is one side of the coil,
tripped different ways.
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.
A Single Pole Single Throw
relay (SPST) is an electro-
magnetic switch consisting
of a coil (terminals 85 & 86),
one common terminal (30),
one normally closed terminal
(87a), and one normally open terminal (87).
When the coil of the relay is at rest (not
energized) the common terminal (30) and the
normally closed terminal (87a) have continuity.
When the coil is energized, the common
terminal (30) and the normally open terminal
(87) have continuity.
NOTE:
When there is power applied to the coil,
the coil sets up a magnetic field in the
windings. When the power is removed,
the field collapses. A momentary high
voltage discharge will occur. This is how
an ignition coil works.
ALTERNATOR
The alternator is designed for output through
the engine operating range. When traveling,
keep an eye on the voltmeter in the dash area.
Normal readings should be between 13 to 14.5
Volts DC. Voltage indications higher or lower
indicate a potential problem with the charging
system. If the alternator output drops below an
acceptable level, a charge indication warning
lamp will illuminate.
080406
060216h
30
080405b
080405c
080405
080405d
Single Pole Single
Throw Relay.