Motorcycle Repair: 87 flhtc, battery cables, random times

Question
on my 87 flhtc,the bike will shut down when first ride of day,usually 3rd or 4th gear.The psi gauge is always pinned at this time.After a few minutes you can restart,the gauge goes down and its usually good for the day unless the bike sits for hours,then it will do it again.Lately at random times the bike will not send out spark then when it does it's very erratic(lots of backfiring).Bought a new coil from harley,have newer fireball ignition(8-3100).Both seem to test out fine but these problems still occur.Where should I turn

Answer
I am assuming that the gage you are refering to is the oil pressure. It sounds like you have a short in the ignition system, which would cause your shutting down. What you need to do is start by checking the battery cables for tightness on both ends as well as make sure they are not worn out. If they are ok, then you will have to start tracing the wires out looking for a broken wire or chaffed wire and making sure that the connectios are good.
Good luck and happy riding
Mike