496 mag ho no start. Code 123 and 133
 

Looking for some help. I have a 2002 powerquest 340 Vyper with two 496 mag ho. The batteries were dead when I tried starting it a couple weeks ago and put the jumper cables and a jump box on it. The batteries are brand new they only went dead because I left the battery switch's on. Now starboard engine won't start. I plugged it into the scanner I get a TPS 123 code and a low voltage 133 code. I swapped PCMS with port, that didn't work. I swapped TPS sensors that didn't work. No breakers are tripped that I can tell. Does anybody know if there's a fuse panel somewhere? Or have any ideas?

Leaving the bat switch ON should not kill the battery, you have a heavy drain going on. What is the battery voltage with key OFF, then ON, then while cranking? Could be your alternator has shorted out if battery stays low

Do you have the proper service manuals to help with diagnostics ? so was power still on when you were changing out sensor(s) and the PCM. hopefully you did not put a known good pcm on the bad engine ??? HUGE MISTAKE to do that. You test the other way around - bad engine PCM on good motor - there is a reason for that keeping known good PCM's alive.

Also code 133 is NOT a fault code anyone thinks it is. Code 133 is the 5 V power low- Meaning this is the 5 V power that supplies all the sensors its 5V reference so that code actually means Excessive current draw on the 5 V circuit in return means sensor(s) and or the circuit shorted to ground. So whats unplug or shorted ?

Just asking is your app DTS ? I do not think it is but still a ?

So since 123 tps swnsos is the only other code does the lead you to believe the TPS wiring has a short or bad ground?

I will definitely check tomorrow . I unhooked battery and hooked back up to see lif that changed the pcm's mind about things .when I re hooked up battery pretty good arc meaning draw. My multimeter read 13.2 with the key off . Will try with it on .thank you

Disconnect the battery then, remove the orange wire from the alternator. Then reconnect the ALT and see if you still get the arc

Tried
 

Ok so I've unhooked alternator completely still have the draw spark on battery . Batteries 12.4v when I turn key on drops .2 volts crank starter drops to 10.5v
I do not have diagnostic manual. What sensor (s) are on 5 v system? If I unplugged one at a time and try it will I find the bad one? Or when sensor unplugged no start?
The dia. Scanner I have is not the laptop one just code reader .

make sure if you have bilge pump FLOAT switch that it is not discharging your batteries.

How about your stereo / amps and all that - possible discharging the batteries ? I would unhook these to see what happens if applicable.

something in the cabin running - fridge or lites - courtesy lites ??

QUOT

I did unhook sub and stereo amps. Shut off all breakers and power in the cabin. Still will not start just cranks and beeps while cranking. Leave key on and beep twice every 2 minutes

The spark with nothing on concerns me, maybe the battery charger

So far as the beeps, I would connect a meter to the 5V circuit, then start unplugging some of the sensors, water pressure, water temp, IAC, TPS and just turn ignition to ON. When the shorted sensor is unhooked, the voltage will go up to 5V