Using alternate crai8 capable pcm

[ATPCR]

@Michael P. Crai8 Covers most all 98 fords including mustang v6, v8, cobra, lincoln town car, grand marquis and crown vic. To get my tachometer working again, could I use a 1998 Mustang PCM in place of the '99 Crown Vic PCM that I have now without any major wiring changes to the 99CV powertrain harness? I'm aware that there are a few pins to move around. Then I could sell off the 1999 Crown Vic P71 PCM to someone with a 1999
Crown Victoria with no tachometer.
By the way, separate topic. On my next 5.0 c-n-p conversion I will be using the 2003 Ford full size PCM. I just can't give it up to use on this first project.
Question. Is there appropriate place here on your forum for parts for sale or would you rather no one attempt to sell related parts, like PCMs or powertrain harnesses, here on your site?

[decipha]

yeah for sale forum at bottom now

that probably dont have a tach out

would be less work to just swap the cluster

[ATPCR]

According to the pcm pin out charts for 1998 Mustang, the #48 pin is active for tachometer. It's that way too for the 2nd generation Explorers.
I wouldn't have imagined that a 1999 Crown Victoria would not have a tachometer, but it doesn't. Hence the non-active pin #48.
If someone wanted to, Mustang instruments probably wouldn't swap out with Explorer and Explorers already have a factory tach in the cluster.

[decipha]

theres two ways the tach can be controlled either hardware or by scp over the obd2 wires to the cluster.

most use the scp doing it digitally over the obd2 wires.

if you want you can dig in to the tach hardware. I knew of some people that did it nearly 20 years ago but pretty sure most of them guys are gone now. More recently theres a company Bostig that does vanagon power train swaps whos mentioned it not too long ago. Probably best to shoot the member bostig here a PM and see if he can give you the details.

IIRC its just adding a few components on the ecu board.

[ATPCR]

Ok. Are these strategies intended to operate v-8 engines with wasted spark ignition systems or coil on plug ignition systems?
I assume that a wasted spark pcm would only have 4 coil drivers.
1998 Mustangs with V-8s have a wasted spark style of ignition and the 1998 Crown Vic has 8 drivers in the pcm for the eight coils?
Or are some the files for wasted spark and some are Crown Vic c-o-p?

[decipha]

98 was wasted spark, cop was 99

a cop ecu can do wasted spark but obviously a 98 ecu lacks the hardware to do cop

best bet just get an 03/04 ecu and swap the cluster
/done

[ATPCR]

Ok. I'll give up on the idea of making the tach work with the 1999 Crown Vic pcm that doesn't have a tachometer output. I will live without a tachometer for now. At least I can see the RPMs on RT feedback.