switch on the rear of transfer case What does it do??

[gt.jacko]

Hi I have just fitted a 4.2 LSE engine and auto box to my defender but have noticed a switch at the rear of the transfer box does anyone know what it,s for and do i need to reconnect it to something???

Cheers :)

[Bowie]

You sure it's not a temp sender?

I'm assuming it's a Borg Warner unit, without a diff lock switch, it's the only connection bar the speed transducer that I can think of.

[gt.jacko]

hmmm could be a temp sensor I guess, I have an official manual and cant find any reference to this switch at all

[Range Rover Blues]

Temp overheat sensor, not fitted to early B-W boxes but definitely to the 4.2

[Bowie]

Temp overheat sensor, not fitted to early B-W boxes but definitely to the 4.2

Got one on both my Rangies, a 1990 and a 1991 :)

[Rossko]

Transfer box temperature sensor, needed on viscous coupling t/b only.
If you want to wire it in, just wire in series with the existing auto fluid temp sensor near the radiator, and either switch getting hot will work the same 'gear warning' light on the dash.

[Bowie]

Transfer box temperature sensor, needed on viscous coupling t/b only.
If you want to wire it in, just wire in series with the existing auto fluid temp sensor near the radiator, and either switch getting hot will work the same 'gear warning' light on the dash.

You mean parallel....

[Rossko]

You mean parallel....

mm, that was from memory buts its been a while !?   I'd have to look it up, unless you've already done so?

[Bowie]

No, just being an electrical engineer, I can tell you that if they are wired in series you need BOTH to get hot before the light will come on.

In parallel either will trigger the warning lamp..

[Rossko]

Okay, I was anal enough to look it up when I remembered  :roll: (I had it my mind the switches were break-when-hot, but they're not at all)

X108 is the autobox temperature alarm switch, which goes on at 130C and is located in the cooler line near the radiator.
X174 is the transfer case temperature alarm switch, which goes on at 145C and is located behind the handbrake backplate.
(X174 is only present on viscous coupling t/boxes)

They should be wired in PARALLEL.  If you wanted to add X174 to an existing X108, the existing wiring should be black (for the earthy side) and black/light green stripe (for the dashboard side). 

cheers, Ross K