GEN 1 Tach reads 1,500 low after upgrades

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Dane

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Just finished a big set of upgrades on my 2012 Raptor. These include a Melling oil pump, full Kooks headers, and a 69mm pulley for my Roush supercharger (along with a million misc things along the way). Fired it up, runs great, but we've found one issue. The dash tach consistently reads about 1,500 low. It didn't do this before. I've tried two different tunes, with the same result. I've compared this with the digital tach and my SVC tuner readings (those two look accurate and match each other). So the truck itself knows the proper RPM, and I don't have any codes. Any idea what is going on here? What caused the tach to get out of whack and how do I fix it? I'm leaning away from it being the stepper motor since it actually works and responds fine, it's just like 0 is now negative 1,500.

Video:
 

1BAD454SSv2

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Try doing a gauge sweep reset in engineering mode . Hold OK button down on steering wheel . Turn ignition key on while still holding OK button , should enter engineering mode. Cycle through different screen should get to one screen and all the gauges will sweep full right. See if that helps you out.
 
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Dane

Dane

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Try doing a gauge sweep reset in engineering mode . Hold OK button down on steering wheel . Turn ignition key on while still holding OK button , should enter engineering mode. Cycle through different screen should get to one screen and all the gauges will sweep full right. See if that helps you out.
Did that. The tach only sweeps into the 5k range.

Here's that video. Notice how far DOWN the tach is at rest.

 
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Dane

Dane

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Negative on the broken needle.
Here’s where we’re at. Removed the needle and reset it to 0-ish. Went right back to the same problem. How? No idea.

Running out of options.

With the truck running, manually moved the needle to the correct RPM. Voila! Everything seems fine.

This doesn’t seem like the way to fix it. But so far it has.

I have no idea what happened. Good news, the Raptor instrument cluster is extremely easy to remove
 

MasterKeebs

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My 2011 recently developed this problem. Dealer quoted me $1300 for a new cluster. If you can, let me know how you were able to get the the cluster so easily. I was under the impression the whole dash had to come off from what I’ve been able to find.
 
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Dane

Dane

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My 2011 recently developed this problem. Dealer quoted me $1300 for a new cluster. If you can, let me know how you were able to get the the cluster so easily. I was under the impression the whole dash had to come off from what I’ve been able to find.
Noooooooope, see the two little screws right above the cluster? Take those out, take out that trim and you'll see more available screws. Unbolt those, pull it out cluster, disconnect harness. Then you'll have to separate the plastic, but it's obvious. It was a very nice surprise that it comes out so easily. Definitely no disassembling the dashing as I was worried about.

Word of caution. Everything is fragile. Be careful and wear nitrile gloves to prevent fingerprints. I can't speak to the longevity of this fix, but it was this or repair/replace stuff - which seems crazy for the given issue. I'd recommend having the digital tach display up while you are doing this, since the digital tach isn't off and lets you see your target.

Perform at your own risk! This was while the truck was running and tach was active! I'm sure it isn't advisable!

Example. RPM is 1,500 low. Rev digital tach to 1,500. Analog tach is at about 0. Physically move the needle to 1,500. Or use whatever numbers you need and works for you, idle, whatever. No magic.

It scares me, but it worked.
 
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