Tacho for a rd28 to TD42 conversion

Did you rev it over 1000 rpm?

Do you have a voltmeter to measure AC volts across the 2 sender wires? Should be around 1v AC at idle

Without the ECU you will need to connect one wire of the sensor to the yellow wire with a black trace (pin 5 ECU connector or pin 44 instrument cluster) and the other wire will need to connect to pin 6 in the instrument cluster (Y-Bl yellow with a blue trace in your diagram).

I'd be interested to know if there was a good result with this.
It could help others in future.

Tacho is all working, got nothing at idle though, my thinking is i could possibly have a faulty instrument cluster, i have no idea if the tacho worked before i pulled the 2.8 out, i never drove it. my blue wire went to the Y-bk and green went to earth.

There's nothing wrong with your tacho. What you're seeing is what the TB45 conversion guys have seen when they connect the TD42 sensor directly to the tacho - nothing below 1000 rpm.

The solution I found was to wire a Dakota Digital box between the sensor wire and the yellow/black that goes to the tacho.
It must just amplify the signal enough to make it work.
My tacho works perfectly now. Checked it with a digital tacho.

ahk, any particular one? http://www.dakotadigital.com/

ill get one of them soon as i have a job again.

but at least ive got something now, ive been curious to know what my rpms are with my 35's and 4.6's

This one..
...

sweet, thanks john.

Hi jaido did you try what Yendor suggested? Would be good to know outcome
Cheers Kimbo

that's what I tried first,
Probably worked aswell but I never bothered to rev the engine I just had it idling and assumed I did it wrong when the tacho wasn't working.

I am having one problem now though and cant figure out where, Fuse 24 (7.5A) keeps blowing and only started since wiring up the tacho.
ive looked everywhere to see if Ive skinned a wire anywhere and may be shorting out, but I got no idea