what is an easy way to figure out if the multi-funtion unit is the culprit in an electrical problem?

also, where is the relay for the turn signals in a 97 disco 1, or is it located in the MFU?

 

OK, I have used this before and I am going off memory here. Theprocedure is in the Rave CD.

Hold the rear defrost button while turning on the ignition. It will beep, then release the button. You can test all of the functions by pressing the buttons for each and it should beep for every input that is ok. You can also hit the defrost again within a few seconds and it will cycle through everything, powering it up for a few seconds sequentially. I'll try to find the procedure tonight if you still need it.

Not sure where the relay is off hand. Get a Rave CD if you don't have one...

 

Dow,
What is your truck doing that makes you want to explore the multi function unit?

 

Ok, this is what I have. Good title for searching, so I'll put it on here if anyone needs it later. Kinda fun to check anyway.

Diagnostic Procedure
1. Close all doors and the tailgate.
NOTE: If the oil pressure switch goes open circuit
(engine is started) during the following procedure,
the MFU will exit the diagnostic mode immediately.
2. Press and hold the heated rear screen switch
and switch on the ignition.
3. Release the heated rear screen switch within 2
seconds and the MFU will beep to indicate that it’s in
diagnostic mode 1.
4. Press the heated rear screen switch; the MFU
will beep twice. In turn, operate each of the following
switches, heated front screen, rear fog guard lamps,
side lights, headlights, front wiper and rear wiper.
The MFU will beep twice each time a switch is oper-ated.
5. Pressing the heated rear screen again will cause
the MFU to enter diagnostic mode 2.
6. The MFU will provide outputs to the following in
order given below:

Heated rear screen relay energised for 2 seconds

Heated front screen energised for 2 seconds

Courtesy lights energised for 2 seconds

Dim dip relay energised for 2 seconds

Rear fog guard lamp energised for 2 seconds

Headlamp power wash energised for half a second

Front wiper energised for half a second

Rear wipe/wash energised for half a second
7. The MFU will then exit the diagnostic mode.