Verado - Parasitic draw diagnosis

[gdink1020]

Hello Verado experts! Last year when using my boat I noticed some long starts when cranking the big motor (merc 200 Verado 1B483XXX), so I decided to replace the battery. I went with an X2 Power Dual Purpose AGM it has 1150CCA 100ah with 220min reserve capacity, which I figured would more than enough to crank the main and power the “normal” house items like bilge, live wells, lights etc. I have my graphs on a separate dedicated battery. When using the boat often I didn’t have any problems, but if the boat was garaged for a period of time it would long start or not start the first time and be good the rest of the day. This spring I’ve decided to track down the parasitic draw and hopefully fix the problem; but I’m kinda stuck….

Using my amp meter I hooked the meter in-line and found 0.80 amp draw on the battery with key switch and master switch for the house both turned off. Through the process of elimination, I narrowed the draw down to the two pairs (pos and neg) of main wires required to run the big motor. This would be the heavy gauge (pos and neg) for cranking the starter and the associated 10ga which I believe they call the DTS wire in the literature.

In further diagnosis, I would begin with the key off, and my meter in-line with both the heavy cranking wire and the DTS wire showing no draw.I then would cycle the key to the run position. You would hear the normal clicks like the fuel pump relay, throttle body cycle etc all with associated current draw (2-8amp) after the clicking stoped the load settled in on a consistent 2amps. I would then switch the key to the off position and the draw would go from 2amps to the 0.8amps instantly and hold steady WITHOUT making any click sounds like it was off cycling. It would hold this draw until you lifted the light gauge wire (or discounted its plug inside the motor) and the motor would click and cycle down and the draw would go away even after reconnecting the plug or reattaching the wire to the battery there is no draw until the key is cycled to the run position and back off. I’m stumped, because I feel when the key is cycled to the off position there should be a series of clicks and down cycling of the engine ultimately resulting in zero drawn from the engine.

Also; I’m not sure if this is associated with the cause of the issue, or just another way to bleed off current from the engine, but if the gear switch is moved into the wide open reverse position; you hear the series of clicks and the draw will disappear. This only works in reverse. My gut tells me this is just bleeding off the “stuck” capacitance in the motor circuits by cycling the shift actuator, but I’m not for sure….

What am I missing?
Anyone have a wiring diagram they could share?
Please point me in the right direction!

[SPORTMOD25]

after engine has been sitting when you say you have a harder start just key engine up without starting allowing the fuel pump to cycle fully. key off the perform again then start the engine. that should eliminate the hard start. as far as your draw you think you have. put the throttle in reverse wide open throttle after keying off and i bet your draw goes down significantly no very little. this is due to your control handle still being active when keyed down for use of the trim. it will auto shut off after a period of time. the reverse WOT will shut it down right away instead of having the delay. what you are experiencing is normal on all digital shift and throttle engines

[gdink1020]

after engine has been sitting when you say you have a harder start just key engine up without starting allowing the fuel pump to cycle fully. key off the perform again then start the engine. that should eliminate the hard start. as far as your draw you think you have. put the throttle in reverse wide open throttle after keying off and i bet your draw goes down significantly no very little. this is due to your control handle still being active when keyed down for use of the trim. it will auto shut off after a period of time. the reverse WOT will shut it down right away instead of having the delay. what you are experiencing is normal on all digital shift and throttle engines

By hard start I mean there was a long pull (like a dead battery) after it has been in storage. The fire/run side of the engine runs fine just the battery capacity/crank side is dead after storage. That’s what sent me looking for a draw on the battery. It act exactly how you describe it. After a period of time, say 15min, you will hear click and cycle off. Putting the throttle in WOT reverse makes it die instantly. Which eliminates that draw. Now I need to go back through and see if there is another draw. There has to be something drawing in the battery overtime.

[SPORTMOD25]

how long is it the boat sitting when the battery is low? and how low is it? when battery is hooked up the ecm in the engine always has a slight draw. even the radio memory has a slight draw, just like your vehicle. the longer it sits the lower the battery will be. if your boat does not have a on board charger hooked to the starting battery i would suggest getting one and plugging it in when not in use so your batteries are always fully charged at all times and ready to go when you are. this will also give you the best life out of your batteries

[EuropeanAM]

You're reading the draw involved with the MPR (Main Power Relay) Active.

To deactivate the MPR you have to turn the key OFF, and shift to REVERSE-WOT. After you hear electronics "parking" return to Neutral.

THAT is the official "OFF" condition.