^^^^^^^ That's because you need to readjust the pole setting dial on the back of the gauge or any of these as described below by Faria ( D & E) mainly what I am talking about but all the rest applies to from Faria

http://faria-instruments.com/site_ma...achometers.pdf

he has smartcraft with digital signals and a PCM controlled engine - they need the digital signals converted to analog signals to be able to even function properly. I believe he is going to have all plug ins to even the analog gauges for this as well if I remember correctly.

and for anyone with this set up on the back of their tach - incorrect tach readings and or a fluctuating tach reading this is the first place to go and turn the pole setting then back to the correct setting.

I do not care if it is set on the correct position, There is reason why it gets thrown off. It has to do with condensation / heat and few other things.

pole setting again if you have the poll settings on the back side of the tach. Analog gauges only.

http://www.pontoonboatforum.com/uplo..._setting_1.JPG

Is it possible I don't have an AGI box? I'm not seeing it. I see a grey wire labeled "tach" in the engire comp, but it doesn't look like it goes to a box. The guage is a mercury guage.

I think this might be simply bad connections at the tach, or an intermittent problem with the tach. After I cut the engine I noticed that the needle did not return to zero, stayed at around 100. I turned the key on and off and it went to zero. The only other thing I did was make sure the connections on the tach where tight. Fired it up and the tach was acting normal.

Thanks BUP, you are always helpful.

Yes very possible since then I want to ask you have a stock OEM Mercruiser HP 525 just asking. but let me post the AGI box and wiring if I can to help to see if you have it. I can not recall a 525 HP Merc without one. I do not see these that much anymore in my area.

Also go back and look at the post above yours 11. and 12 and read them. Again the simple things first like I said in other post.

The tach wire does not go through the aig box,,,it does go thru the ten pin main connector as a gray wire,,,,

I found this up here but thought 4 sure this would have been a huge before you and with diagrams. I guess not. click on the links in the thread also. Maybe not much help to you but I am trying to find the wiring diagrams online.

http://www.offshoreonly.com/forums/g...ue-gauges.html

I already posted in post 4 - grey wire and is located main wiring harness pin 2.

reread post 4.

just saying

When my boat was repowered with 496HO smartcraft motors, the only gauges that worked were the tachs and the water pressure gauges because they were tee'd in to the water system. Oil pressure and water temperature were inoperative. I am in the process of installing Livorsi Vantage View gauges right now. It's a really slick setup and pretty easy to setup. I would think the 525's would have to have the AGI box if everything else works properly, although the tach's don't need it to operate.

Well I want to be clear as glass here.

I never said the tach grey wire was in the AGI box - post 4 states that as clear as it can be.

Next I never seen a stock HP 525 PCM engine with analog gauges of any sort with out an AGI convertor box - with out the AGI box the gauges will not read. this is all I can find.

http://livorsi.com/catalog/smartcraft.htm

Please click on link and then read all agi box descriptions this might help whomever. If it does great if not I am sorry I tried.

Again check all easy stuff first as mentioned a bunch.

next I listed other possibilities. That's all I can do.

Link below about the agi box read the descriptions - all of them.

http://outboardparts1.com/merc/13AG61/457.pdf