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They sent an inquiry to MAZDA to see if they’ve seen that problem before but they said they hadn’t.
After a week both fuel pumps came in snd were replaced but they’re still having problems with it.
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.... Mazda got back my dealer and said there is a wiring harness that is under car that has a cover over it that is defective. Mazda knows about and what happens is one of the connectors doesn’t seal. If it gets wet it can short out and damage both fuel pumps.
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I had previously decided to not post my thoughts on this again, because I had already been quite negative about what they had done so far, and didn't see any point to adding to what I'd already said. However, with folks now talking about things like possible recalls, and patching a defect, I now feel the need to say what I really think about everything that's been reported here.
First off, according to the dealer's story, Mazda did not know anything about this issue of both fuel pumps failing simultaneously, with a possible relationship to a wiring harness, However, just a short time later, they did claim to be aware of the issue, assuming that's what "Mazda knows about" from the OP's post above means. Perhaps a case of Mazda initial support being weak? Or possibly just BS? Who knows?
Next comes the question of this defective 'cover'. Unless they disassembled the entire fuel pump harness all the way up to the front of the vehicle, they must be referring to the fuel pump assembly cover, which is located under the rear seat. First off, I'll agree that liquid getting past that cover, could enter the fuel pump connector under it and short out the pump. However, this area of the vehicle is so well protected, that there's no possible way for anything from outside the vehicle to get to that area - unless someone tries to use it as a boat.
So the only ways I can think of for liquid to get to that cover would be if someone spills a drink on that area of the back seat, or if a window or the moon roof was left open, letting lots of precipitation in. So to the OP - did anything like that happened with this vehicle?
Now could they be talking about some other cover on another area of the fuel pump wiring harness? Perhaps so, but that entire set of wires runs in a very well protected part of the vehicle, and it's impossible for me to imagine external moisture getting anywhere near another connector in the fuel pump circuits.
What I've mentioned so far is in the questionable category, but I'll concede that it's POSSIBLE for liquid to come through the fuel pump cover (or a different cover), run down into the low pressure fuel pump connector, and short out that pump.
But at this point, their story goes from what's possible, to the very highly improbable IMO. The high pressure fuel pump is a non-electrical, totally mechanical pump, driven by the exhaust cam. So for this outfit to be saying that a short in the low pressure fuel pump connector also took out the high pressure fuel pump is, I believe, detached from reality. And if they claim that the HPFP failed because of no fuel being delivered, that would be totally illogical as well, because who designs a downstream pump which could fail in a no-load situation? So for me, when one part of their story has such a giant red flag, that creates lots of doubt about the entire thing.
I obviously have no way of knowing how much (or any) of what they said is true, but do believe that at least some of their current story is a cover-up for the part hanging that they did previously. Of course, they will ultimately get the vehicle fixed and can say whatever they want to, regarding what the actual root cause and repair was. And there will be no way to refute anything they say.
Regardless of how this thread turns out and what they say, the bottom line on this for me is that I'm not going to lose any sleep over fuel pumps getting shorted out by liquid coming through a cover. But if other folks choose to remain concerned about all of this, that would certainly be up to you.