Hook the wire directly to the battery and perform the troubleshooting steps outlined by MSD. You may be chasing a problem that could be a defective component. http://www.msdignition.com/page.aspx?id=3206
I already had to replace this msd box because there was no spark... I was on the phone with msd and they guided me through the steps to test it... It was new so autozone replaced it... the replacment is in the truck I was just worried about not having 12 volts to the trigger wire in start mode... msd says the street fire box will run on as low as 10 volts, but I don't know if they mean the trigger wire or the Big battery wire....
I have used MSD boxes for years..... The small trigger wire on the MSD box doesn't even need 10 volts to work properly..... This wire simply triggers a relay inside the MSD box that connects the large red that goes to battery power, the large red is the one the box actually operates off of..... Hope this helps.....
OK I checked my voltage at the big red wire coming from my battery, It drops to 9.3 volts while cranking over the car... I have it on the charger now, the battery is a older one with only 450 cold cranking amps... Dose anyone think that could be the problem ? should I upgrade to a bigger battery ?
That battery sounds like it's getting weak, I would replace it with one with a little more cranking amps..... Don't try to start the car on the charger with an MSD, they don't like that somtimes.....
woop's I did try it with the charger hooked up, hope I didn't kill it... only tried once tho so I'll cross my fingers.... I'm thinking the 9.3 volts is my problem, with the key off the big wire has 12.75 volts... Back to the drawing board...lol
I have a 500 cold cranking amp battery on the charger now, we'll see how that go's.... 50 more cranking amps than the one im using now...
Whats wierd is if you do a spark test that msd says to do, I don't get any spark at all.. thats with the key in the on pos. and over 12 volts at both wires...
When load testing a battery, you load the battery to half the cold cranking amps for 15 sec and it should not drop below about 9.5-10 volts. So if yours is dropping to 9.3 with the starter, She is a weak battery for sure. Dead No, Weak yes.
