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Discussion Starter #1 (Edited)
I have a 2012 Honda Pilot Touring. We have replaced the alternator in my truck 3 times since October 2019, once every month. The check charging system light comes on just before I lose power and it dies. The first time there was oil all over the alternator. I replaced the engine valve gasket and there hasn’t been any oil on any of the alternators since. But something is ruining these alternators. I do not have any warning lights on the dashboard other than the check charging system. This last alternator was tested as the others have been and was told the alternator was good. But I was broke down on the side, we swapped the battery, drove it home and the truck ran fine for about an hour and shut down again. Any ideas as to what could be the problem? Anyone else experience this issue?
 

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Assuming for the moment both replacement alternators were "good", then there may be a PCM connection or PCM control issue. Since the replacement alternators work for a while, I might suspect a connection issue (the 4 pin) at the alternator which gets disturbed when you swap parts. Pull the connector and look for white or green crusties, that none of the pins or sockets are pushed in or spread apart, rodent or abrasion damage to the wiring etc.

White vinegar is great at dissolving crusties, followed by a light rinse of water, a blast of compressed air to dry, and then a shot of contact cleaner (Deoxit, CRC, etc).

And examine the main power lug to the alternator to make sure it is clean and no wire damage.

A PCM control issue is beyond a typical DIY to troubleshoot or repair.

When the alternator is working properly, at idle with headlights on, a DVM on DC volts should measure 13v to 14v or so across the battery terminals. With the DVM on its AC volts setting it should read less than 100mv rms.
 

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Charging is monitored by the gauge control module via CANBUS from the engine PCM. You should see the charging system warning in the gauge cluster when the alternator isn't charging. VERIFY that the charge indicator lights when the key is in position 2 (engine run). The diagnostics for the Indicator not working are pretty involved if you do it by the manual method (without Honda HDS), Fuses 10 (7.5A) and 23 (10A) in the under dash fuel/relay panel are critical to the indicator function, so a good place to start. After that you get to diddle with switches in a specific order to start the cluster diagnostics sequence, then read flashing lights and beeps, plus the needle on the speedometer and the ODO mileage indicator for diagnostic message.

For the alternator and charging, assuming the cluster indicator is working correctly: Check/replace fuse 3 in the under-dash fuse/relay box. it's a 10A fuse that supports the charging function. From the diagrams it's not real clear how it relates to charging function, as the field excitation part of the PCM box isn't detailed well.

After all that, Honda can read the diagnostic trouble codes from the PCM for you..
 

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I had this problem on my 2012 Crosstour V6. The Variable Valve Timing Solenoid mechanism is most likely leaking oil between it and the spool. The oil drips down into your alternator killing it. Remove 3 bolts on top and you will find a couple of rubber gasket (one with a screen) that needs replacing. Hopefully this is where your leak is and not the spool underneath. Replacing the spool requires removing the valve cover and rocker arm assembly. I just did the whole job spools and all because my VVT solenoids went bad and the valve covers were leaking. The rubber gasket set is what you likely need if you do not have engine codes related to the VVT solenoids. They recommend replacing both left and right if you replace solenoids. The gasket set is not available to U.S. market at your Honda dealership. Here is an Amazon link for a OE Honda Japan import if you just want the gaskets. Takes 2 sets to do both right and left. Amazon.com: 15815-R70-A01 15845-R70-A01 Cylinder Head Solenoid Valve Gasket VTEC for Honda Vehicles: Automotive
Check fitment for these gaskets. I did the entire assembly. After market Part # VVT282 (Left) and # VVT237 (Right)
 

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It took me 4 times to find an alternator that did not fail under 6 months ..the reman alternators SUCK... I had no issues with the ones purchased from rockauto ..I think they even offer "new" not sure
 

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Buy the DENSO Reman from RockAuto.

Are you buying a cheap junk local parts store brand?
 

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Buy the DENSO Reman from RockAuto.

Are you buying a cheap junk local parts store brand?
If this was referring to what I posted it was the best brand that Autozone, pepboys and advanced auto sold. that's when I purchased one from rockauto..
Btw At $264 out the door at these places I don't really consider that cheap junk :)
 

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If this was referring to what I posted it was the best brand that Autozone, pepboys and advanced auto sold. that's when I purchased one from rockauto..
Btw At $264 out the door at these places I don't really consider that cheap junk :)
Of course not cheap in price but junk.
 

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If this was referring to what I posted it was the best brand that Autozone, pepboys and advanced auto sold. that's when I purchased one from rockauto..
Btw At $264 out the door at these places I don't really consider that cheap junk :)
No - that was directed at the OP. I know that the auto parts places charge a ton for theirs.... you are paying for their warranty.
 
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Buy the DENSO Reman from RockAuto.

Are you buying a cheap junk local parts store brand?
It took me 4 times to find an alternator that did not fail under 6 months ..the reman alternators SUCK... I had no issues with the ones purchased from rockauto ..I think they even offer "new" not sure
Go Denso.
Honda remanufactured are Denso.
 

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Didn't have any issues with the one with Rock auto 110 K later and still going "knock on wood"
 
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