Rev Counter not working on 'E30' 325i Motronic 1.3

[E30325imanc]

A little bit of a strange setup, but bear with me.

I have an E21 with full E30 motronic wiring from a series 1 325i. The instrument cluster is from an 87 325i and its Rev Counter stopped working one day (although it did start working again intermittently for a while) and then I had the wiring swapped over for the later 1.3 motronic.

Question is what do I need to get it working, keeping in mind the wiring is now 1.3?

Any help would be really appreciated ”“ thanks

[E30325imanc]

Anyone please?

[eta]

Your motronic 1.3 loom will try to sent the engine speed wire (black) thorugh the circular C101. Your E21 may not take the engine speed signal through the main centre harness (which leads to the C101 in the engine bay). The engine speed signal in a E21 may come through another route. It does in a E28 may the E21's are similar.

[E30325imanc]

Okey Kokey, still not quite sure but this gives me something to go on - thanks!

[clarko74]

This might help:

http://www.e30zone.net/modules.php?name ... c&t=181277

[E30325imanc]

Hi Willnz, yes the full motronic loom, econometer used to work. If this was the case, any leads from there?