DIY: Replacing AC Amplifier

smijus

Brat and Curd Aficionado
Premium
Location
Milwaukee
Car
2007 FX35 AWD
Name
Justin
So I was having some cold start problem detailed in this thread: https://www.infinitiscene.com/search/1/?q=11403-cold-start-problems

I knew that my battery was good so I did some research and it seemed like the AC Amplifier was the best culprit.

So here is the process of replacing the AC Amplifier.

First off, the AC Amplifier is the most expensive plastic box that I've ever bought and this is what it looks like.

P1000587_zps45457d03.jpg

There are three cable connections at the back of the unit.
P1000588_zps7c018c67.jpg

The AC Amplifier sits immediately behind the AC Controls under the main display stack in the middle of the dashboard.

To replace your AC Amplifier, do the following:

1. Take a plastic pry tool or something non scratching and slowly pry around the bezel of the center display panel.
P1000586_zpse3f94515.jpg

2. You'll need to slowly make your way around the entire bezel until it starts to pry up, before you pull the center stack out, there are two cables that need to be disconnected. One white connector, seen here from the bottom,
P1000585_zpscd16d916.jpg

...and one black ribbon cable seen here from the passengers side.
P1000583_zpsd1e675d2.jpg

Once these cables are disconnected, you can remove the entire center stack and set aside for the time being.

3. You will now see the guts of your center stack, and the AC Amplifier, the gray plastic box at the bottom. You will need a Philips head screwdriver to remove the 4 screws holding the center stack in place.
P1000582_zpsdbf45088.jpg

4. Now you can pull the entire center stack slightly out of place so you can access the 2 Philips head screws that hold the AC Amplifier in place. There is one on either side of the unit, remove them both.
P1000578_zps77b26a69.jpg

5. Once these two screws are out, you should be able to pop the box out of place and more easily access the 3 cables at the rear of the AC Amplifier.
P1000580_zps44eadfbd.jpg

6. Remove the three connectors, replace with the new AC Amplifier and reconnect the 3 cable assemblies.

7. Put the AC Amplifier back into place and return the screw on either side of the unit.

8. Slide the Center Stack back into place and return the 4 mounting screws back into place.

9. Before returning the faceplate, re-attach the white cable and the black ribbon cable.

10. Place the bezel back into place and slowly push firmly around the entire outside of the bezel, you'll feel the face click back into place.

11. Start up your car and go through all of the functions on the center stack to ensure that everything still works.

12. You're all done. :)
 
Very nice! Look forward to hearing how it works out for you, especially long term.

For $345, it better fix it haha.
 
Great step by step smijus. I hope that the AC amp will solve all of your starting issues. Back when I replaced mine in 2010 my car started up better than it ever had since owning the fx. Since replacing it I never once had any starting issues and it's been in the low teens up here in MA.
 
Do you have a part number for this? And where did you order it from? I thought I read somewhere that the part number is different for the newer ones that replace the old bad ones
 
I bought mine through http://www.infinitipartsusa.com

Enter in your vehicle information and then navigate to Body Hardware > Instrument Panel > Cluster & Switches
The part is typically labeled FX35 Amplifier in the list.

For my 2007 FX35, it was Part Number 27760-8Y71A
 
Thanks for the writeup smijus. I absolutely love the FX but hate dealing with the cold start issue. Especially when it is the wife who can't get it started. I've had the same issue since i bought mine in 2007. The dealer never could replicate or isolate the issue. Now it is out of warranty and i checked with the local dealer and the charge to replace the AC Amp is $1500. This is Canada :eek.:
Btw. I have the standard aluminium trim what is your trim? I like that look.
 
Thanks for the writeup smijus. I absolutely love the FX but hate dealing with the cold start issue. Especially when it is the wife who can't get it started. I've had the same issue since i bought mine in 2007. The dealer never could replicate or isolate the issue. Now it is out of warranty and i checked with the local dealer and the charge to replace the AC Amp is $1500. This is Canada :eek.:
Btw. I have the standard aluminium trim what is your trim? I like that look.

Search up "infinitipartsusa" and order the ACamp from them, and replace it yourself following the steps above. You will save yourself over $1000.

As for his trim it looks like the standard aluminum to me...
 
Search up "infinitipartsusa" and order the ACamp from them, and replace it yourself following the steps above. You will save yourself over $1000.

As for his trim it looks like the standard aluminum to me...

Yep. that is the plan. I thought that trim is aluminium but mine looks more brushed aluminium while this trim has kind of spots on it..almost has a carbon fibre look. Must be my eyes :)
 
Those aluminum trim pieces are the "sport" version. The standards are just plain brush aluminum.
 
Ha, I didn't know that was the case. I've never actually checked to see if my car had the speedo recall. Now I would be kinda pissed if that was also part of the deal. Oh well, something to ask at the 60k service.

Andy's right about the trim, that the "sport" version, so it's more of a textured aluminum look.

---------- Post added at 11:00 PM ---------- Previous post was at 10:58 PM ----------

Also, with the temps very low, into the negatives last night, had no problem starting this morning. It would appear that the issue has been resolved..
 
Hey Justin, if the AC Amp is included in with the speedo TSB, you can always put the old on back in and have it replace by the TSB and then sell the one you bought on here. :wink:
 
Yes I did, depends if you have intelligent cruise or not, if you do, it gets replaced....if memory serves me right.

---------- Post added at 04:47 PM ---------- Previous post was at 04:41 PM ----------

I'm wrong, although they did replace mine for some reason, its not part of the TSB, it's just replace the ICC unit and reprogram the AC amp.
 
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No issues with my FX but would it makes sense to buy an entire nav unit with AC amp used for $325?
 
I think it depends on the age of the Nav unit. If it's an old AC amp, it may not fix the issue.
 
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