Hello All,

I am hoping that someone can help me out here. I have a 1998~1999 model year Volvo 502/8.2 GSi complete engine with EFI system. Engine only has 20 original hours on it and is rated at 415hp. Physically the EFI system looks almost identical to the HP500EFI setup. I have a 1999 272 Baja with a Mercruiser 7.4MPI 310hp engine. My question: I wanted to replace the 7.4MPI with the Volvo engine and was wondering if the wiring harness plug would be plug-nplay…Mercruiser vs Volvo; or will I have to make some changes. They look identical. Anyone out there with wiring diagrams? Please help.

Thank you.

The wiring is nearly identical between a Volvo Penta and a Merc.
I have a 1997 Superboat that originally had a Merc 7.4 Carb motor. I bought a 1999 Volvo 7.4Gi and just plugged it in and turned the key.
The only thing that did not work was my trim gauge and the alarm under my dash.
The Volvo engine had an alarm mounted on the engine and I wired the trim gauge outside the plug.

Thank you for the info Pat.

Do you remember which pin or wire color it was?

Thanks,
Bill

I ran a new wire around the plug because my Volvo harness did not have the pin. I think it may have been #10, but I'm not 100% sure; it was 4 years ago.