I put a post in the electrical section but no-one replied; https://passionford.com/forum/techni...o-operate.html
I have been told there is wealth of experience and knowledge on this forum, so maybe I just posted in the wrong place, at the wrong time. Some one on here must know what is needed to get the original Tacho to work?
Where I am now; I boughta late model V6 Capri dash panel as mine was originally a 4 cylinder. I connected the trigger wire to the green wire at the ciuster and it did work but the needle would flick randomly down to the stop or up beyond resonable rev range, each time returning to what I think was correct but I couldn't leave itlike that. My trigger wire comes from the ECU whichis the original Ford one. I also tried taking a lead from the EDIS but it was just the same. I bought a cable from Trigger Wheels; https://www.trigger-wheels.com/store...n-uk/p129.html this seemedto mirror a system I had seem online where a tacho signal is taken from the 3 green wires at the coil pack. It's fitted, there is no flicking but it's just like everything before in slow motion if that makes sense. Trigger Wheels have recommended a pull up resistor, which I have ordered but it seems to have got lost in the post.
Iwould like to know if I am barking up the wrong tree, before I do any more additional wiring. Appreciate any advice or info anyone can give, Thanks in advance.

 

My car using an Maxx ECU required a pull up resistor for the original tacho to work. No idea if that’s what yours requires.

 

Thank you for your reply. It sounds similar to the way I have been going, so that sounds a bit more positive. Your diagram is how I would wire the resistor (if only the thing would come in the post!), except for the different ECU, so if that's all it needs I will be happy.

 

I have no experience on tachos from Capris, but I do know that in the Sierra some tachos don't like the signal from the EDIS module, as they are designed to work from the negative connection on the coil. Other Sierra tachos actually do work correctly with the EDIS, but I don't know what the difference is between them. A lot of BOA conversions use the original Granada tacho for that reason. I was lucky and the Sierra tacho in my car does work correctly with the BOA.

 

I also have a small aux guage pod, one of which is a tacho and it works OK but it is a modern one and works from the same ECU signal I have been using. I wondered about a Granada Tacho or even just a slim modern one and fit it into the dash pod but I was advised it was too much cutting of the pod and too much likelyhood that the printed circuit would get damaged, it is wrapped around the back of the pod, so I didn't go down that route. THere are so many Capris around with the BOA and BOB engines, I am thinking someone must know what to do but all I have came up with on FB and so on is peope who have done it in the past but can't quite remember how they did it. Thanks for the reply and info anyway.