For L300 Delica 4D & 4G
Replacing the OE mechanical fan is a great way to increase performance and cooling. Eliminating the mechanical fan also eliminates the power required to spin it, resulting in a power gain for the drive-line. This also eliminates the possibly problematic mechanical fan clutch and give the Cooling system better control.
This will require removing the radiator from the van and removing all the OE fan components.
NOTE: This is still an untested modification. Therefore this guide should be for reference.
Parts:
- Electric Fan Kit: Derale 16831 – It’s almost the perfect size!
- Electric Fan wiring Kit/Parts
- 36mm Hose Sensor Adapter OR Adapter with Switch
Buying a quality fan kit that can move enough air is critical. You have probably heard people say that electric fans don’t move enough air. I would be willing to bet they never calculated and matched or exceeded OE CFM. Cheaper kits are failure prone and known to under-deliver. This is why we spent the big bucks and went with this premium kit from Derale. This kit moves 3,750 CFM. This closely matches our calculations for CFM. We get ~3,800 CFM @ 4200 RPM, assuming the fan clutch if fully locked up. This kit also moves 3,750 CFM no matter what RPM the engine is at, perfect for those low RPM climbs when keeping EGTs down.
You can download the Fan Calculator below.
Calculations:
Shroud Installation:
1. Remove the radiator and fan+fan clutch. Remove the shroud from the radiator.
2. The lower radiator inlet interferes slightly with the shroud. This is a result of the weird elbow fitting. Remove the fans from the shroud and trim the entire shroud down ~0.25″ to fit under the elbow. Ensure to allow space for the hose itself to be clamped to the elbow.
NOTE: I have not checked fitment with the available aftermarket aluminum radiators. They have a different style elbow, so this interference may not be an issue on those radiators. Straight inlet L300 radiators also exist, like this one: Straight Inlet Radiator
3. To mount the shroud, first place the supplied L brackets on the studs as shown below.
4. Since the shroud has been trimmed down the vertical slots in the brackets will need to be elongated to line up with the slots in the shroud. A die grinder bit in a drill will do the trick.
5. Add clip Nuts to the L brackets so that the shroud can be installed without requiring tool access from the inside.
6. Since the shroud has been trimmed the fans/hardware will now make contact with the radiator core. Cut down the 8 aluminum spacers so that the fans no longer contact the radiator. I recommend cutting them down significantly to make the shroud a more effective plenum. The fans will protrude father from the shroud (toward the engine). Flip the fastener orientation so that the threaded portion sticks out the back.
7. Install the 36mm sensor adapter and sensor (switch) into the upper radiator hose. Ensure the adapter is grounded.
Wiring:
Below are the parts and wiring diagram for the fan kit:
-Choose an appropriate temperature switch usually around 180F is usually good. You can match this with the thermostat opening temp. Ensure it fits the hose adapter female threads.
-Each fan has its own fuse and relay. These fans are high current, so best practice that they have their own line. 10-12 Ga wire recommended.
-Relay signal supply is fused.
-Temperature switch switches ground.
-Signal wires (relay pins 86) wired directly to battery, instead of ignition source. This lets the fans run after the car/engine is shut off. This eliminates the need to idle and cool down. The fans run after the engine is off to eliminate heat soak, then automatically shut-off once cool enough. Many modern cars are configured this way.
