MSD installation

Porsche 2 · 02-09-2009, 11:34 AM

Most advice suggests the large red +ve MSD wire should be connected directly to the large +ve (from battery) starter motor cable, thus to a positive source that is live all the time, independent of the ignition switch. There is a similar constant positive power source at the small fuse panel under the plastic cover in tne left rear of the engine area which I plan to connect the large red MSD wire to, as it is near to the point where I am mounting the MSD unit. Does anyone think this is not a good idea?

Porsche 2 · 02-09-2009, 11:38 AM

I forgot, the car is a 1981 911 SC.

fred cook · fred cook's Garage

The MSD unit will pull a couple of amps per 1000 rpm. Just make certain that the fuse will handle the load. I ran a lead off the main power lead on the starter for the MSD in my SC. It is easy to do and you can run it thru a piece of small diameter vacuum hose for extra protection. Just use some tie wraps to run the new lead along a protected route. Piece of cake!

vash · vash's Garage

same year as yours, my car is an 81. when i bought the car, the PO pulled power from one of the three fuses in the panel. i fried one. i rewired it to the starter lug, with a proper inline fuse. i feel better about it. running the wire is easy if you follow the AC lines down the right side. you can poke them thru super easy.

rick-l · 02:05 PM

Quote:

Originally Posted by Porsche 2

Most advice suggests the large red +ve MSD wire should be connected directly to the large +ve (from battery) starter motor cable, thus to a positive source that is live all the time, independent of the ignition switch. There is a similar constant positive power source at the small fuse panel under the plastic cover in tne left rear of the engine area which I plan to connect the large red MSD wire to, as it is near to the point where I am mounting the MSD unit. Does anyone think this is not a good idea?

How can letting the My Spark Disappears unit run 24 hours a day be a good idea?

Nevermind I see the MSD has a switched input.

Porsche 2 · 02-09-2009, 02:05 PM

Thanks for all your comments. Will report back after installation.