I have had '90 12V in my '85 crew cab for a few years.
It is a clean swap using all the factory wiring and dash.
Everything other that the cruise works right now.

I am looking at swapping the 727 tranny for a Getrag, and would like to put a 2nd gen Motor in at the same time.
I will also be doing the 2nd gen intercooler install using the Non intercooled core support [in the sticky]

I am looking at installing a '94-'97 Cummins motor in the engine bay and am looking at re-using the simple '90 wiring harness.

I am wondering what sort of wiring problems I may run into during this swap.
I would like to keep the guages on my factory dash working.

I could swap the Non I/Ced 1st gen style alt. on the P-pumped motor if that helps re-use the wiring / Voltage regulator on the firewall.
Or would the '94+ altenator be fine, as the '94+ style use the PCM as the regulator?
The wiring on the back of the Alt. looks the same '90 to '94+.

I have no wire plug in, on the '90 wiring harness, for the crank position sensor on the '94+, but that shouldn't be an issue, unless I want a tach...Right?

I fiqure I could wire up something to make the '94+ fuel shut off work, or just put it on a cable pull.

Would love to hear from someone who had done this before, as changing somethings on the motor BEFORE it was in the engine bay would be much easier.

Thanks!

 

You should be able to just reuse all the sensors off the 1st gen engine and bolt them onto the 2nd gen engine. I wouldn't bother trying to use any of the wiring from the 2nd gen engine, as I can't see it being of any benefit in your truck. If you do get a full wiring harness with the engine, you can strip the wires out needed for the fuel shut off solenoid, its easy to wire and pretty straight forward.

 

For what it's worth I'm running a 1st gen regulator (external) on my alternator, had a problem with the PCM doing it for me. One less thing for ya.

 

Thanks for the posts guys!
I can always count on the people on DTR to help me with my dodge truck projects

Tate,
Most of the sensors on the motor look like they take the same wire clip ins - '90 to '94+.
I will try them before installing the motor in the Crew though...
Swapping a few sensors would be a cheap way to get the wiring to work, as I would have the 1st gen sensors on hand.
I can get the other side of the 2nd gen factory fuel shut off switch wiring, so I am thinking that is the best route.

Gorms I am happy to here I can keep my 1st Gen regulator and just wire up the Alt. as is.

Just fiqured I ask a few questions in case I am missing something right in front of me..