Another MFA issue

[jon525]

Hello to all,

The MFA on my 1990 Scala hasn't worked since I bought it, display is clear and keeps perfect time. The problem is nothing happens while using the end button to scroll through the functions on both 1 and 2. I have removed the fuse to reset and nothing, had clocks out etc, continuity ok from stalk down to 4 pin plug and then from there up to the plug entering the clocks. Decent earth on the cam cover and the vacuum pipe was connected ok, so my final thoughts were the black unit the vacuum pipe connects to or the screen unit itself?. Is there anything inside these that could be at fault?.

Many thanks

Jon

[Jack92]

Not going to be much help here but I had a similar issue and it all seemed to test through. The clock also had issues on mine so swapped the clocks which fixed that but MFA still didn’t work.
Ended up swapping the stalk as a gamble but it paid off and sorted it. Still haven’t a clue what was wrong.

[jon525]

Thanks Jack92

The stalk seems to check out fine but if one comes up the right price I will give it a go, I believe there are two types of digital display, one just a clock the other includes MFA function?. This is why I wondered if the fault could be there, also the vacuum unit on the back of the clocks?, but is that just to do with fuel economy etc?.

Cheers
Jon

[mark1gls]

Yes I believe the black block on the back of the instruments is for MPG as the hose on the back goes near the inlet manifold.

Some of the other functions should still work even if the black box is faulty like oil temp, out side temp as they have different sensors.