MSD 6AL fuse?

[squaredeal91]

I read that the 6AL has its own internal fuse and supposedly not recommended to add one in because it's something like 1amp per 1000rpm? So is it redundant to add one or a good Idea? Was thinking 5amp or something. Any thoughts?

 

[Ricko1966]

I am sorry I can't answer your question,but I will state something my instructor told us in GM circuits and meters class. Your meter has an internal fuse to protect it. If you use your meter incorrectly,by accident this fuse will protect your meter. But now you have a dead meter and probably don't have the correct fuse. Make a fused lead for your meter with a value just below the meter fuse. Now you have a fuse that is easily checked and replaced and your meter is protected.

 

[squaredeal91]

Thanks ricko! So now I need to find internal fuse number size.

 

[nvrenuf]

I have my MSD instructions that I can check later.

 

[nvrenuf]

Here are some pics of the wiring pages from the instruction papers from my (analog) 6AL.

I have a 30a fuse on my ignition power wire but only because I powered my ignition and some accessories from an add on fuse panel.

If you need an actual wiring diagram, just let me know what distributor you’re using and if there are any other MSD accessories.

 

[Matt69olds]

The idea of having an unprotected wire running across the engine compartment has zero appeal to me.

Use a fusible link, or overkill fuse.

On my Olds, I have the 6AL box mounted behind the passenger headlights. It’s on a place with lots of airflow and out of the way. I used 10 gauge wire with an 20 amp fuse, with the wiring protected by factory style wire loom and the factory style plastic harness clips.

Obviously, an 20 amp fuse is overkill, based on MSDs current demands. But if that fuse does blow, either the MSD box died, or there is something seriously wrong with the wiring. There will be no nuisance fuse blowing!!

 

[squaredeal91]

Thank you all! I will be upgrading. My power wire because I learned it's way too small.

 

[squaredeal91]

Currently running factor hot wire but it's like spaghetti so I'm going to wire in a relay using stock wire for trigger so I don't canabalize it. Had no idea I needed a 10 gauge wire for hot. No accessories power anywhere so I need to pull it from battery but already have so much going on there now as it is.
I'm thinking of making an off battery hot post to move all my eyelets from the battery to clean things up.

 

[Matt69olds]

You don’t NEED 10 gauge, assuming the msd draws an amp or 2 per 1000rpm, 14 gauge is sufficient. I used 10 just because that’s what I had at the time.

Put the fuse as close as possible to the battery, and run the wiring carefully.