Sprinter 3500 V6-3.0L DSL Turbo VIN 45 (2007)
Condenser Fan Motor Relay: Description and Operation
Controls - Rear
Description
DESCRIPTION
The rear A/C condenser fan relay (1) is a electromechanical device that switches fused battery current to the rear condenser fans to help dissipate heat
from the rear A/C system. The rear condenser fan relay is energized when the relay coil is provided a ground path by the control circuitry within the
A/C-heater control. The condenser fan relay consists of a plastic housing with an integral mounting bracket (2) and wiring connector (3) with eight
electrical terminals.
The rear condenser fan relay is located on the top left side of the vehicle, beneath the rear cover.
Operation
OPERATION
The rear condenser fan relay is an electromechanical switch that uses a low current input controlled by the A/C-heater control to provide a high current
output to the two rear A/C system condenser fans. Two movable, common feed relay contacts are held against the fixed, normally closed relay contacts
by spring pressure. When the electromagnetic relay coils are energized, they draw each movable common feed relay contact independently away from
the fixed, normally closed relay contacts and, holds them against the fixed, normally open relay contacts. This action allows high current to flow to each
of the rear A/C condenser fans as required.
When a relay coil is de-energized, spring pressure returns the movable relay contact back against the fixed, normally closed contact point. A resistor or
diode is connected in parallel with each relay coil to help dissipate voltage spikes and electromagnetic interference that can be generated as the
electromagnetic field of the relay coils collapse.
The rear condenser fan relay is connected to the vehicle electrical system through a wire lead and connector located on top of the vehicle, near the left
side of the rear A/C condenser.
The rear condenser fan relay cannot be repaired and must be replaced if inoperative or damaged. Refer to the appropriate wiring information for rear
condenser fan relay and rear A/C system wiring diagrams.
