there are some inportant things to know about external MSD boxes..
to make them live.. you need to hook the thick black wire to a good ground that is connected to the body but also the engine block/heads..
there are a few racers who have created 4 ring terminal harnesses for the ground..
one ring terminal for the back of one head.. one for the back of the other head.. one for the distributor housing if you are running a module inside the distributor.. and the last one to the firewall or where ever the MSD thick black wire is connected..
when the spark comes out of the coil.. it goes thru the wires and across the spark plugs. but it does not end there.. it has to make a complete circuit.. back to the module that is hooked to the coil.. that is the thick black wire..
guess what.. if you have the thick black wire hooked to the battery as the directions say.. all you spark return has to go up the negative battery cable to get to the long thick black cable to the msd box..
with a firewall or engine ground.. the spark return path is a LOT shorter.. and there is less chance to have the spark return try to get to the module ground via some other path..
please print and perform this test..
http://i.imgur.com/WMDprhm.jpg
test 5 is to the connector near the battery or to the threaded stud on the starter relay and you will expect 7/10ths of a volt with the engine running and the headlights on of voltage drop.. as the stock designed charging systems on Dodges go a LONG way..
with the additional current draw of the MSD box.. you may want to think about running an additional wire from the alternator output to the positive battery so you bypass the long long wiring thru the amp meter.. you can also remove one amp meter nut and move the free wire to the top of the other amp meter stud nut.. and install the extra nut on there. that bypasses the amp meter.. unless it shorts out.. and it should not with only power on one stud. the reason for the alternator to positive battery wire is to remove the multiple passes thru the bulk head connector also..
this is all up to YOU... please at least perform the voltage drop test i linked..
15 inch braided ground straps are available at most parts stores to hook the engine/head to the firewall in the help section.. 3/8 ring on one end.. 1/4 on the other end. .
this is important for the reason that the alternator puts out its electrons on the negative side. and almost 2 volts more than the battery can supply.. run the voltage drop test to prove its properly hooked up..
thank you for listening.
my brother in law had a 68 charger.. somehow he took it to el mirage.. bone stock 383 4barrel automatic car.. ran 156 MPH. the motor only lasted a few days after that.
decades ago i worked for a paint store with my dad.. they sent me on a rush delivery to the burbank studios.. dukes of hazard set.. i got there.. general lees parked all over the place. i made my delivery.. got the invoice signed.. just turned to leave to check out the generals and the crew in the sound stage parted at the big door.. 2 german shepherds on leash walked in followed by cathrine bach in full daisy duke costume. what little there was of it.. think she looked good on the TV.. you should have seen her in person. that image is burned in the back of my brain.. i completely forgot to look at the generals as i was leaving.