[Mk2] [Generic] Rev counter dead?? Replaced capacitors, still nothing

[jimGTS]

After a number of weeks of carrying out a wire tuck, finally started the car up.
Ran perfectly fine, however my rev counter is dead.

Now I realise the tacho gets its feed from the ignitor after a Google, which is the black wire on the ignitor plug.

I've traced this back to the fuse box. Which in turn goes to the body harness across the car to the passenger kick panel.
I also get continuity on one of the black wires there as well so there's no break to that point.

I've followed the st205 bgb and everything checks out




Last resort I thought it must be the capacitors on the tacho, but replaced those and still nothing.




Also swapped ecus and again no change.

I'm running out of ideas??

[jimGTS]

after finding this super helpful electrical link


i believe my ignitor wire for the tacho, is fixed to the wrong pin in the fuse box.

on connector EA3, it should go to pin 5.
i believe i have it on 16 (which is for the a/c clutch), so its probably going to nowhere.

fingers crossed i swap these over and im good to go.

http://mr2.bordeauxgroup.com/1993%20MR2 ... iagram.pdf

[jimGTS]

all sorted!

just a heads up for anyone interested in where the tacho/rev counter wire goes.


on a gen3 at least, the black igniter wire (one for the tacho) goes to the -IG port on the diag port.
from there it goes to pin 5 on the AE3 connector in the engine bay fuse box.

from there its on the body harness which feeds to the cabin passenger side, under the sill and to the large IE1 plug in the footwell on pin 13.

on a gen2, the wiring diagram suggests it doesnt route to the diag port, but goes straight to the fuse box from the igniter.
its the black and white wire from the igniter that splices into the diag port (on a gen2).


least those are my findings.

[gnzyza]

Good to know, glad you sorted it