2005 xc90 alternator not charging

[goldy12]

helo I have a xc90 that does not seem to be charging battery tested good, abs light on along with triangle center of cluster buy no battery light, light comes on with key. battery voltage at fat wire, 8.3 volts at green/white wire and have wave pattern on same wire when running but voltage does not change still only 12.5 volts. wave pattern is not perfect but I do have wave pattern. I am leaning towards alternator is there any other test I can do to verify that its the alternator. thanks guys

[jimmy57]

You have a bad alternator. The waveform is the LIN communication to ACM/voltage regulator from CEM. It should be a pulse pattern with regular flat line segments between the digital pulses. When the signalling is present and it isn't charging then it leaves only alternator as the problem.
You likely have a lot of low voltage codes in the various modules including ABS. The brake module is very sensitive to voltage as pump motor and solenoid valve operation requires good supply voltage.

[cameron514]

I have searched and searched on repairs and FINALLY did the amazing Alternator replacement. I bought a ReManufactured from AdvancedAuto with promo for like $180 total. Anyways..... 
I got my old one out new one installed which took all of 8 hours. 1 day later My POWER SYSTEM FAILURE SERVICE URGENT came on the dash. I found that my LIN wire connector on the Alternator was loose and would only slide up and down and would NEVER clip into place onto the Alternator. I bought a replacement Alternator plug off eBay for $8 and used cut off the OLD Connector. I used a Tap Splice connector and plugged the new harness / connector on to the Alternator but it was stil not charging. I thought F**K I may have to drop the Alternator again and have it tested. I also NOTICED my Washer T connector on the Pass side was also broken on the bottom which dumped Fluid down towards the alternator, so i replaced that as well. 

Here is what I'm getting at....I NEVER saw this on ANY FORUM, so I wanted to SHARE in case someone runs into this as well. I have a iCarsoft Scanner. I thought WHY NOT checked and see what codes it may display. I showed the ECM having a ECM-U012087 " Lost communication with starter / Generator Control Module.

ALL I DID WAS ERASE THAT CODE AND BOOOOMMMM THE CAR WAS BACK TO CHARGING!!!!!! It has been 2 weeks since I have cleared that code with no issues charging. CHECK YOUR VOLVO ERROR CODES WITH A SCANNER, AND ERASE! I hope that helps someone! 

[onn8582008]

Thank you Cameron will try this now!