Mercury Clean Power Fuse Keeps Blowing

[rpr]

2019 300HP Mercury V8 Verado, Serial #2b646603

My 5-amp fuse labeled Mercury Clean Power, located off the main shutoff switch in my battery compartment, keeps blowing. The few posts I’ve been able to find regarding this fuse mention that the Verado will not start when this fuse blows. My motor runs with this fuse blown, which I’m thinking means that something came wires wrong from the factory or the dealer wires something wrong when they added the 5th auxilary battery (for steering the kicker with the Verado power steering unit).

However, I’ve studied the Merc recommended wiring diagrams for this 5th battery configuration and as far as I can tell everything does seem to be wired correctly.

The only other thing I can think of that’s worth mentioning is that we do frequently have bad lightening storms here in GA in the summer and I do frequently find the dock breaker tripped or the GFCI on my slip tripped.

Do others periodically find this fuse blown after dock/GFCI breakers trip?

Does the fact that the boat still seems to run fine with this fuse blown mean I have a wiring issue?

[rpr]

I’m also seeing a few posts that say the positive and negative terminals on the DTS Mercury Clean Power harness with the 5-amp fuse should be connected directly to the cranking battery. The positive terminal of mine appears to be connected to the Perko main shutoff switch in my battery compartment.

[SPORTMOD25]

clean power is exactly that. needs to be connected directly to the battery

[rpr]

Ok, but why is the motor still running fine with the 5-amp clean power fuse blown. I could be wrong but all other posts I’ve seen on this indicate the power to the dash is cutoff and the motor should not start with this fuse blown.

[EuropeanAM]

I’m also seeing a few posts that say the positive and negative terminals on the DTS Mercury Clean Power harness with the 5-amp fuse should be connected directly to the cranking battery. The positive terminal of mine appears to be connected to the Perko main shutoff switch in my battery compartment.

Clean power SHOULD be connected directly to the Cranking Battery. It does NOT power the dash- it is clean power for the PCM (clear from other drains and draws).

Wondering if you might perhaps have TWO clean power harnesses in this boat for some reason (one at the engine and another at a J-box, perhaps). If that's the case, that would be why it runs and starts fine with this one blown.

Determine if the above is the case before proceeding- but either way, this is something that your dealer should be checking for you.

[rpr]

Thanks Don. Interesting thought but I don’t see any other clean power harnesses, at least not that have a direct connection to the battery. It is strange that the motor still seems to run fine with the clean power fuse blown.

I’m in a strange situation with dealer(s). The only Triton dealer here does not have any Merc certified mechanics. A Tracker dealer who has Merc certified mechanics was able to get a conditional approval to do some work on the boat, but that authorization was then terminated by Triton.

So on anything that’s in a gray area (i.e.: is the manner in which the clean power harness(es) are wired in the boat a Merc issue or a Triton issue) it can get complicated. This rig has spent the vast majority of its short life in the shop and I’m doing my best to try to work out the remaining issues myself.

Also just got the wiring diagrams and figured out I had two dead pumps (Recirc 1 and Livewell Pumpout) because they were connected to the wrong harness plugs...it’s been crazy.

[EuropeanAM]

I'm almost starting to cringe at the though of this- but could you post a few pictures of your battery and switch connections?

Here's the catch: Proper rigging of the engine and battery are the responsibility of the SELLING DEALER (and if the problem is improper rigging, that is not a "defect").

Does become a gray area if Triton pre-rigged the boat, though.

[RangerNate]

I have this gut feeling that the fuse was blowing at rigging, and was bypassed. The PCM is probably powered from another source.

[rpr]

I don’t have any pics of the battery at the moment but here’s a pic of the back of the switch panel. Note they have the Line (+) side of the switches on the left connected to the Load (-) side of the switches on the right.

Attachment 418732

[EuropeanAM]

Technically one row of those should have been flipped over so the "line" was down the center row. Not a significant concern, however (they will work).

See if you can get some pictures of the battery and battery rigging, as well as the J-Box and components behind the dash.

[rpr]

I’m not sure if any of these pics will reveal anything, but here goes:

[EuropeanAM]

Please check and confirm where the wires on this plug are running to:

[Triton19x2]

Your less than 3 hours from Don. Even if it was not covered under warranty, I would be willing to pay him to at least diagnose what is going on there. You are doing a good job keeping your cool...I would be pissed

[rpr]

Sorry for the delay, I just got out to the boat yesterday. That plug runs to a terminal block that ultimately goes to a TH Marine dash gauge for my jackplate, and then back into a harness that presumably runs to the jackplate. Several pics appear below.

[rpr]

And for what it’s worth, the red wire from that plug has an in line 10 amp fuse.

[rpr]

Don, if the above wiring of that plug does not look problematic to you, recall that I had to have the local Tracker dealer rewire the boat per Mercury’s recommended protocol for a 5 battery configuration (so the kicker can use the Verado’s power steering when the Verado is not running). Maybe that’s the issue.

Here is the diagram Merc provided for use with the new 300HP V8 Verado’s:

[EuropeanAM]

If that red/black wire plug is running from the J-Box up to the ACCESSORY RELAY and is connected to the large RED and BLACK wire terminals, there is a problem there.

The Accessory Relay should have ONLY power from the BATTERY on the large RED terminal. Any ACCESSORY items are powered from the PURPLE terminal (which is active when the key is in the Accessory or RUN positions).

[rpr]

Ok, I dug into the wiring a bit more today. The red and black wires from the plug in the J Box run directly to the large red (constant power) and black wires on the terminal block under the dash. The red cable from this plug is labeled “Mercury Clean Power, 5 Amp Fuse”, yet it has a 10-amp fuse in it. So I do have two Clean Power harnesses in this boat for some reason.

When the 5-amp Clean Power fuse in the battery compartment is pulled and the 10-amp Clean Power fuse under the dash is left in, the dash lights and the engine starts. When the 5-amp Clean Power fuse in the battery compartment is left in and the 10-amp Clean Power fuse under the dash is pulled, the dash lights and the engine starts. When both fuses are pulled, there is no dash power and the engine does not crank.

So it does look like the factory bypassed the Clean Power harness in the engine compartment and put one in under the dash with an oversized fuse. Mind boggling.

Would love to hear next step recommendations that won’t kill the rest of my season. Don, I’ll PM you my contact info.

Here’s a few additional pics:

[Savage]

Definitely need to find out WHY this fuse holder has a "10" AMP fuse in it, when the label clearly states that the fuse size should be ("5") FIVE AMPS ????

[EuropeanAM]

If there is a Clean-Power harness between the engine and the cranking battery- REMOVE the one under the dash (completely).

I responded to your PM also- suspect there may be more than one battery accessible to the engine (correct)?