A few electrical problems

[TehAgent]

Hi all,

As this is my first ever post, this is the car in question

Its a 1997 2 liter turbo petrol executive.

Right i have a few problems i need sorting out, i have only just purchased the Vehicle so do not know my way around it completely yet, also, although I'm good with fixing cars, I'm not too good on technical names so bear with me.

From my research on-line, i have a intermittent speedometer reading problem, and have found and removed the black bitron box from behind the glove compartment. but would like to test if its OK or not, does anyone know if these can be tested with a multimeter? and if so, what pins to test.

Also, if its not the sender unit, where exactly is the speed sensor? is it on-top of the gear box, underneath the Air-filter? or is it only accessible from under the car with the tray removed?

Also, the last Owner of the vehicle had a problem with his radiator fans not coming on at temperature, so he called out a electrical engineer, who has; what looks like soldered two wires leading to a manual switch from the relay area on the fans, to inside the bonnet, as this is a bit impractical for usage does anyone know how i can fix this problem? and get it so the fans are back to the way they should be?

Any help in these matters would be very much appreciated, thank you for your time in reading my problems

Regards

TehAgent