ECM Location

[FBGNO]

I have a 2000 RD with an E7 330-350, with the ECM on the passenger side. My engine block has a crack in it and I want to replace the engine with a good used engine. When I look into used engines they ask me what side the ECM is on. I have a shot to by an engine out of a 1999 MR fire truck with an E7-350 with only 23,000 miles, but I have no way of asking what side the ECM is located on. Do I need to know that specifically or is it a non issue, such as, Don't worry all 99's are on the passenger side. If it does make a difference, what is the difference? Is it just a matter of the ECM harnesses and is there a way to switch the parts from the existing engine to relocate the ECM on the new engine to be able to use in my truck.

[Mack Technician]

23K, nice find! I'd guess it's a left side ECM on MR.

The folks asking you "what side" want you to be able to drop the engine in without making any external hardware adjustments.

The base blocks are the same for these year-class engines, that's what matters. You can swap a bolt on component or two, especially if you have some left side revisions between engines, won't matter. When you have the donor and replacement in your possession your golden, throw nothing away till your running.

 

 

 

Edited November 7, 2019 by Mack Technician

[FBGNO]

That's what I was thinking, but wasn't sure, I didn't want to be stuck with a 3000 pound paper weight Thank you so much for taking the time to reply it is greatly appreciated.

Frank