Super Spec Rev Counter

[AndyW]

The rev counter in my newly acquired Super Spec doesn't work - Rover 2000 engine with MEMS ECU and standard RH supplied Escort instrument binacle (I think).

Can anyone give me details of how the rev counter should be wired up at sender and instrument loom so I can check all the connections.

Also, reading some early 2005 posts in these forums there is talk of the rev counter not working when it came from RH, and they subsequently issued a newsletter with a fix. Does anyone have a copy of this?

 

Cheers, Andy

 

[edbond]

Do u have the wiring diagram for the kit?

 

Ed

[AndyW]

Hi Ed, yes I have the original wallchart wiring diagram (issue 5). But the bit about the rear of instrument cluster just lists the wire colours and socket pins. No idea what wire does what! And I haven't pulled it out yet to see if all connections are good.

 

I'm guessing that the rev counter takes pulses from the coil (?), but the coil bit of the wiring diagram only shows 2 wires to ignition switch multiplug and ECU pin 25. Whereas my coil has actually got 1 wire on 1 term and 3 on the other.

 

I'm trying to find out if the extra wires were part of the later RH fix and what they do / where they go.

 

Andy

[Guest 2b cruising]

Some rev counters run off the alternator.

Might be worth looking at that part of the wiring.

Edited May 17, 2016 by 2b cruising

[AndyW]

Wanderer - do the additional wiring instructions from 2005 mention rev counter/tacho wiring? If so I would like to get a copy if you can scan or copy them.

[AndyW]

Wanderer - PM sent, thanks

[AndyW]

Got them, many thanks. Now for some studying.

[alanrichey]

Just to muddy the waters, my coil has just a single wire to each terminal One is white and one is white.green,

 

We do know that the tacho is not fed from the ECU (figures, as it is an Escort cluster and a Rover ECU) but not sure how it is operated.

 

This is what the back of the cluster looks like

 

 

So there are 3 terminals labelled 'E', 'B+' and 'S'. Not surprisingly the 'B+' terminal is connected to the 12V ignition switch supply. I initially assumed the 'E' was Earth and 'S' was Sender, but the 'wallchart' wiring diagram indicates the 'E' terminal is not actually connected and the 'S' terminal is connected to the +ve side of the coil.

 

Don't know if anyone can explain how that works ? Doesn't make much sense to me.

[Longboarder]

Looks like standard tacho connections. B+, 12v. E, earth. S, negative of coil. That's certainly what I would try first. That would co-exist with a 12v switched live to the + on the coil and coil negative with two wires, one to the S on tacho and one to the triggering terminal on the ECU. Can't see why that wouldn't work.

 

Nigel

[IanS]

Tacho off alternator was for diesel where there is no spark.

[AndyW]

Got the tacho working in the end. It needed rewiring according to the later instructions provided by RHE, details as follows:

 

I had 2 wires connected to coil -ve. Remove white/black wire connects coil -ve to engine loom for ECU pin 25. Join this instead to black/green wire that connects to blue connector pin 8

 

Then modify the wiring into the blue connector block which clips to the Escort instrument binnacle:

pin 6 - remove existing black/green wire to coil -ve. now empty

pin 8 - remove white/black wire (‘S’ connector on Tachometer from coil +ve).

replace with existing black/green wire (to coil -ve), and white/black wire that goes to engine loom for ECU pin 25.

pin 9 - previously empty. make new pin and connect to earth

pin 12 - remove white/green wire and terminate. replace with white/black wire to coil +ve (‘B’ connector on Tachometer).

 

Good luck!