Motorola to Delco Alt Swap

[mark mcj]

Hello,
I currently have a 1980 MC120 with a Motorola alternator. As I'm sure most here know it has a 4 wire, external voltage regulator. This alt. is rated at 37 amps.

I am attempting to make this boat and engine as bulletproof as possible and would really like to swap the current motorola alt for a Delco single wire.

My thoughts are #1. the Delco alt design is one of the most dependable ever designed and #2. I'll be able to pick up at least 18 to 25 amps by going to a custom rebuilt marine grade Delco.

Mounting does not seem to be an issue, I might need to fab a customer bracket and use standard spacers.

The only other thing I can see right now is some minor rewiring to the coil as the current setup feeds the coil off of the Motorola alt.

I think I have a plan but wanted to throw it out here and see how many holes can be shot through it.

 

[bruceb58]

Re: Motorola to Delco Alt Swap

Sounds like a good plan.

 

[dan t.]

Re: Motorola to Delco Alt Swap

smart move ,go for it

 

[cr2k]

Re: Motorola to Delco Alt Swap

The old wire going to the coil was probably to excite the field on the old one.

Just check for 12v on the + side of the coil to be sure (with ign ON).

if good then just DC all the old wires and run a heavy to the battery.

 

[mark mcj]

Re: Motorola to Delco Alt Swap

Thanks for the replies.

It should be an easy upgrade.
I was really suprised to see the current Motorola is rated for only 37 amps.
That's pretty funny.

I plan to use the spare purple wire in the engine harness to run +12v to the + side of the coil from the key.

Thanks again.