MSD Box Shorting out !!??! Anyone else had this problem?
 

I went to start the car and it ran like crap. Be mindful I changed nothing on the car. It ran fine before than now like crap. Only thing extra I added was the APC tachometer. I also found out that I had a short in my cooling fan wires, which would have nothing to do with the spark.

The car would start then wouldn't crank at all. I checked the MSD box and power is going into it but not going out to the coil. Anyone else ever had an MSD Box go out?

It was the MSD 6AL box.

Re:MSD Box Shorting out !!??! Anyone else had this problem?
 

Yeah, had this happen to me once...but it wasn't the box's fault, there was a slice in one of the wires and it shorted out the unit. That's probably what happened to yours at some point...MSD's are notorious for being fragile like that. But before you ditch the unit, check your coil and all the wires first before you send the 6AL to it's doom...specially since they're not gettin any cheaper. Also, where did you hook your tach up to? The MSD should have a seperate tach output. Using the negative side of the coil sometimes will short out the units as well.

Re:MSD Box Shorting out !!??! Anyone else had this problem?
 

The tachometer was hooked up directly to the MSD box. I will check all of my wires and see what could have shorted out the box. The only short I had in the car was the Meziere Electric water pump. Could that have shorted out the box?

Re:MSD Box Shorting out !!??! Anyone else had this problem?
 

I don't really think that would've shorted out your box, usually it has something to do with the outputs getting shorted that does it. MSD's use capacitance discharge, so think of it this way...it's kinda like taking a car audio capacitor and charging it up, then shorting both terminals together. It may still work after the first time or so, but after a few more the capacitor will just blow up.

Re:MSD Box Shorting out !!??! Anyone else had this problem?
 

I've repaired an MSD box, it blew the inverter power transistors and a fusible link where the power line goes in.

Re:MSD Box Shorting out !!??! Anyone else had this problem?
 

---- just call them up and ask them to replace it. I emailed them on the cost of a boost knob for one of their boxes since I saw one on ebay really cheap that was missing one and they never responded to me but they did send me a boost knob, so if anyone needs one I have a brand new boost knob for the MSD box ;D