picca00

ok i got a tough question here. i just finished getting the 502 mag into the 18' glastron after working on a custom fuel system. engine starts and runs fine, but i have to hook up the shift interupt switch some how and dont know where to run the wires to. its a 96 502 mag mpi and im using an alpha drive so i need to have the interupt switch. (bravos dont use this switch). my question is where do i run the wires from the switch to.? in the carburator version they go to the distributor or coil, but i have a mpi motor so i know its different. i wanted to look at a wiring diagram from a 350 mag mpi with alpha set up, but didnt know how related to computer functions would be or how different the switch set up would be? so if any body can tell me where to run the wires from the shift interupt switch id really be grateful. thanks jay

Sledge Hammer

Not sure about the switch. Not to burst your bubble, but I am wondering if it is worth the effort. I can't imagine you are going to make an Alpha live behind a 502 for any time at all.

crapr6

Sorry I cant help you with wiring it up, I know what the shift interupt switch is for but what will happen if it isnt hooked up? Reason I ask is my buddys 3.0L 4cyl motor w/ alpha 1 drive dosnt have the shift interupt switch hooked up and everything shifts smooth and he has no problems. Sorry for hacking your thread its just iam wondering what the deal is with it.
Erik

Young Performance

You can tie it in to the purple wire in the 10 pin harness. You can look for the wire just after it comes out of the plug on the the rear of the engine. Just cut the purple wire and run it in and out of the interrupt switch. The purple wire is what powers up the ecm, fuel pump, ignition, etc on an efi engine. It is the same wire that goes to the kill switch up by the dash. You could also use the pink wire that runs between the coil and distributor. This will only kill the ignition. Either will work fine. Hope this helps, Eddie.

picca00

you cant shift out of gear back into neutral with out it for me... i have to shut off engine to disengage.

eddie what about the est line (white) that comes out of the ecm at pin J1-10 and connects to the distributor at pin d?
thanks for the help jay

crapr6

Gotcha, my buddys motor is carb so he has it set at 650rpms idle and thats probley why he can pull his out of gear so easy. I guess with you having fuel injection lowing the idle is not going to happen. Good luck wiring it up.
Erik

MacGyver

Probably a little off topic. But does your insurance provider know about your upgrade to a 502 MAG? Better let them know, otherwise you could be denied a future claim.

picca00

cant get insurance that is worth anything, my boat is a 1978, it got a total custom build thats super tech. alot of money and time was spent here. also i try to stay away from idiots that dont know how to drive. insurance would be nice if i could get it valued at 20k! but that wont happen.

Pismo10

I agree, wire it into the kill switch. Drive it easy, small prop, higher rpm range and the Alpha will last a while.

bowtie

picca do you have pics of that boat. I have the same boat that has been abandoned in my yard that is in nice condition. I've thought about restoring it, such a classic look. Never thought about putting a 502 in it though.