Service manual

ManualsBrandsBENDIX ManualsDryerAD-1 AIR DRYER

WIRING THE HEATER/THERMOSTAT

1. Determine the vehicle’s electrical system voltage and

make certain that the AD-9

™

air dryer that is to be

installed contains the same voltage heater. Use the

AD-9

™

air dryer part number to confirm the proper voltage.

The AD-9

™

air dryer is available with either a 12 or 24

volt heater which uses 75 watts of power.

2. A two lead, 12 inch, wire harness with attached weather

resistant connector is supplied with all retrofit and

replacement AD-9

™

air dryers. Connect one of the two

leads of the wire harness to the engine kill or ignition

switch. The remaining lead of the wire harness must be

connected to a good vehicle ground (not to the air dryer

or its mounting bracket). A fuse should be installed in

the power carrying wire; install a 10 amp fuse for 12 volt

heaters and a 5 amp fuse for a 24 volt heater.

3. Use 14 GA wire if it is necessary to lengthen the wire

harness provided with the AD-9

™

air dryer. Make certain

all wire splices are waterproofed.

4. Tie wrap or support all electrical wire leading to the

AD-9

™

air dryer at 6 - 8 inch intervals. Note: Wires should

have sufficient slack and not completely taught.

TESTING THE AD-9

™

AIR DRYER

Before placing the vehicle in service, perform the following

tests:

1. Close all reservoir drain cocks.

2. Build up system pressure to governor cut-out and note

that the AD-9

™

air dryer purges with an audible escape

of air.

3. “Fan” the service brakes to reduce system air pressure

to governor cut-in. Note that the system once again builds

to full pressure and is followed by a purge at the AD-9

™

air dryer exhaust.

4. It is recommended that the following items be tested for

leakage to assure that the AD-9

™

air dryer will not cycle

excessively.

(A) Total air system leakage (See Bendix publication

BW-5057 “Air Brake Handbook”).

(B) Compressor unloader mechanism.

(D) Drain cock and safety valve in first (supply) reservoir.

(E) All air connections leading to and from the first

(supply) reservoir.