The main control box with temperature dials for the kit is around 12cm wide x 7cm high x 4cm deep, and Mod-Wise suggest placing it away from manifold heat or water ingress areas under the bonnet…

The best place is probably next to the air filter above the radiator but difficult to access here…

I know some people have mounted it to the front chassis cross member (over or next to the VIN), which is easy to do with a couple of cable ties; but personally decided the best place would be to the right of the washer bottle attached to the wing; out of the way, but still easy to access. (I considered mounting it to the left of the washer bottle, but the carbon canister is located behind here in the wing, and may get wet since is where the bonnet gap is, so probably not a good idea).

I removed the control box cover (by undoing the screws in each corner) and mounted the housing by measuring up and drilling a couple of 2mm holes into the wing, and countersunk 4mm holes through the control box housing, then attached the housing to the wing using a couple of No.8 4mm x 16mm chipboard type screws as shown in pictures below (with the washer bottle moved to one side to allow easy access): I then screwed back on the control box cover with dials.

Control Box Housing

As per the provided kit guidelines, I then mounted the two torpedo shaped thermostat sensors to the water pipe from radiator outlet pipe, using a couple of cable ties and foil tape wrap as shown in pictures below, and coiled back the copper wires from the thermostats as best could back to the control box now mounted into the housing.

Themostat

Themostat with foil

Next I looked at attaching the relay connectors to the incoming power and fan connections, and hit a bit of a snag because the plastic housing of the connectors to the relay were T shaped rather than square shaped ones used to my fans as shown in picture below with square type on left and T shaped on right. I guess TVR may have used various connectors over the years (my Griff was manufactured in 1995), or my fans might not be original (although I’ve no previous records of them being changed)

Connectors

To resolve the issue I removed the “Lucar” blade type connectors and swapped the square and T shaped plastic housings of the connectors from the fans and the connection on the relay to the original incoming power feed.
The “Lucar” blade type connectors are fairly easy to remove from the plastic housing using a small flat screwdriver to bend back the retaining clip. The only hard bit was carefully looking at the picture sent with the kit to work out which connectors from the relay to swap, and making sure black connected to black when connectors were plugged together. Also with the connectors removed from the plastic housing I took the opportunity to clean them with sandpaper.

With the relay connectors modified I then mounted the relay to the air filter box by drilling a 2mm hole through the box and using a No.8 4mm x 16mm screw.  I then ran the cable to the control box round the top of the radiator. See the picture showing the relay mounted to air filter box and connected to fans with plastic connector housings swapped.

Realay In Situ

Last came the job of connecting the relay lead to the otter switch on the header tank. I tried to route the cable round the nearside of the radiator and then along the chassis but found that the cable was not quite long enough. So instead ran it along the underside of the water pipe to the radiator inlet, moving the protective sheathing to the end nearest the otter where the cable ran along the pipe, and using cable ties next to the jubilee clips of the hoses to hold it in position. See the picture showing wiring to the otter switch.

Otter Switch

Testing was fairly straight forward, as described in the notes that came with the kit. With the ignition on but engine not started, I turned down the dial with red dot (full fan) and… nothing happened! As described in Mod-Wise’s notes this was probably because I’d connected the relay to the wrong connector on the otter switch, so swapped it round and found the fans kicked in at full speed, so far so good.

Then I tested half speed operation and worked ok, so finally shorted the otter connections (to simulate otter switch kicking in) and fans came on at full speed overriding the control box, all good.

Final thing to do was tune the dials on the control box to give the desired results…
Using the water temperature gauge in the car I set the dials so that the fans came on at half speed at around 78’C, and full speed at around 83’C.

With the car stationary outside on a cold winters day, and engine running at idle I found that the fans alternated between half and full speed keeping the temperature just above 80’C, so looks like the kit works fairly well; but given fact cannot hear the fans running at half speed from the drivers seat, I think will need to add a couple of LED’s to the dash so can see how well works out on the road in the coming months with current temperature settings…

See the picture showing the control box in situ with washer bottle replaced.

Control Box

What would do differently, if did it again:

1. Mount the control box a bit higher: so easier to get to bottom screws of cover and slightly more to the right so screen wash water pipe given a bit more room

Things extra to do:

1. Fit the voltage top-up wire from the relay to the starter circuit when next get car up on ramps
2. Add a couple of LEDs to the dash so can see when fans are running at half and full speed
   

If require any more information, or got any suggestions let me know…

Stefan (msg)