User Manual
18735-InstructionSheet
Derale Performance, Los Angeles, CA 800.421.6288 www.derale.com
INSTALLATION INSTRUCTIONS
SINGLE STAGE ELECTRIC FAN THERMOSTAT
PART # 18735
(Continues on reverse side)
KIT CONTENTS
QTY. DESCRIPTION
1 Thermostat Switch
1 3/8” NPT Thread-in Probe
1 Push-in Probe
1 1 x 1 Foam Pad
1 Retaining Clip
1 Blue Ring Terminal
QTY. DESCRIPTION
2 Blue Butt Connectors
1 Blue Wire Tap Connectors
4 4” Wire Ties
1 20 Amp Fuse Holder
7’ 14GA. Red Wire
2 Blue Female Connectors
THERMOSTAT PROBE INSTALLATION
This kit includes two thermostat probe options.
Choose the option that best fits your application.
(See Diagram #1)
(See Diagram #3)
For best results we recommend installing the probe as close as
possible to the water inlet of the radiator. (See Diagram #2)
1. Take the brass probe and thread it clockwise onto the thermostat.
2. Carefully insert the probe/thermostat assembly into the fins of the radiator
until thermostat is flush with radiator.
3. Install the 1 x 1 foam pad onto the Push-in Probe.
4. Install Retaining Clip onto the Push-in Probe until tight. (See Diagram #1)
Option 1 - Push-in Radiator Probe
Option 2 - Thread-in Radiator Probe
Option 1
Placement:
Installation:
IMPORTANT
This single stage electric fan thermostat will
control one electric fan with a MAXIMUM DRAW
OF 15 CONTINUOUS AMPS.
Please read these instructions completely before beginning installation
Push-in
Radiator
Probe
Down-flow Radiator
Option 2
Placement:
Installation:
Note:
Locate a 3/8” NPT port either on the radiator, waterneck, intake
manifold or cylinder heads.
1. Using Teflon tape or suitable sealant install the probe into the 3/8” NPT port
on the vehicle.
2. Using a 3/4” wrench tighten the probe.
3. Carefully thread the Thermostat Switch clockwise into the Push-in Probe now
installed on the vehicle. Sealant such as Loctite can be used for permanent
installation. (See Diagram #3)
DO NOT TIGHTEN THERMOSTAT WITH A WRENCH, HAND TIGHTEN ONLY.
Diagram #2
Push-in
Radiator Probe
Water
Inlet
Water
Outlet
Cross-flow Radiator
Water
Inlet
TOOLS NEEDED
12V Test Light
Wire Stripper
Crimping Tool
3/4” Wrench
Radiator
Foam Pad
Retaining
Clip
Push-in
Probe
Diagram #1
Thermostat
Switch
Diagram #3
Thermostat
3/8” NPT
Brass Probe
3/8” NPT
Brass Probe
Water Jacket