i have never had to use a ground in the past, but when testing the ballast i did notice the bolt in the ecu didnt ground the volt meter, but the screw in the washer bottle did. i mite have another ecu, how can i make sure its grounded?
all mopar ECU's pull there ground from the case, if it wasn't grounded you likely fried it;
you can check ground like you did with a test light; but make sure your postive cable is disconected and your test light aligator clip is hooked to the postive insted
that way if you have no ground you won't fry it before you have a chance to get it running