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Water on driver side floor board.

TWINN

New Member
Joined
Jan 9, 2012
Messages
8
Hello all;

I have a concern (major Concern) about my 07 avalanche. I live in San Diego and it has just started to rain; however, I have noticed that the floor area on the driver side is wet. (soaked) at first I presumed it to be from my feet not being dry when I entered the vehicle but then yesterday night I briefly examined the carpet and the cushion that is underneath. I did see a grommet with a cord coming through it. Could this grommet be the source of the problem and letting water come inside the cab? (keep in mind, it was dark out when I checked) I did not see any tears or anything on it. Do you have any suggestions to where this water may be coming from?
 
I do not have a sunroof.  :cry: 

(An update) I have went out on my lunch break to examine the water intrusion further. I have noticed that the water did not come through the grommet on the floor board.

Now, I have to do some more digging to properly locate the problem.

any suggestions would help. .
 
When you open your door you will see a rubber boot and wire harness coming out of the door. The rubber boot sometimes come off and allows a water leak. To fix you just push boot back in place.
There are lots of threads on this site discussing water leaks and there are several causes.
Good luck finding the source.
 
Thank you for the knowledge.

I have not searched for the rubber boot but I will take a lot later today on my lunch break. This problem is causing major concern. I don't want the smelly odor or even worse, have a rotting floor board.

About the water in the back seat, So far I have not seen any. I have checked thoroughly for any mid gate problems that I may have. So far its good, the weather strip is in tack and is well.

Once I have checked for the boot, I will come back and write my findings to you all.

Thanks again  :wave:
 
i had this exact problem. I bought a used 2008 AV LT 5 weeks ago. the 1st week I had it, it poured here in Nor Cal. The cab took on huge amounts of water. the dealership took the truck in to service for a week and fixed the leak. They said it leaks where the wiring harness AND where the parking brake cable enter the cab from the engine compartment. apparently this is a common problem on 07 and newer av's.

good luck!
 
ces said:
i had this exact problem. They said it leaks where the wiring harness AND where the parking brake cable enter the cab from the engine compartment. apparently this is a common problem on 07 and newer av's.


I too, had this EXACT same problem, in my 2005.  So it isn't just the GMT900s... it's in the 800s as well.

The main wiring harness grommet can become unseated out of it's hole.  It can be that way for a year or two or three without you noticing, but I caught mine relatively early... within the first few rains after taking delivery.  Water slips inside the firewall and down under the carpet, saturating the jute padding underneath.

The main wiring harness grommet is about 4.5 inches in overall diameter.  The best way to find out if it is unseated is at night.  Put a droplight inside the cab at the driver's floorboard facing towards the brake pedal.  Release the hood latch, and then look under the hood behind the fuse box, at the firewall, to the right of the master brake cylinder.  If it's dark outside, and your grommet is unseated, then you will see light coming through your firewall that you shouldn't be seeing.

This light test is a lot easier to do to verify the problem before getting your hands dirty.  To properly seat the main wire harness grommet might require removing the fender to firewall brace on the driver's side, and removing the cover to the underhood bussed electrical center (fuse box).  I don't own a 900, so I'm not sure how it is configured, but I doubt it is too much different when it comes to a main wire harness about an inch and a half thick, going through a large grommet about 4.5 inches in diameter.

I also removed the threshold trim, the kicker panel trim, and elevated the carpet and the jute padding while placing small heater fans on the floor board to dry the area out completely.

Once my grommet was fully seated correctly, I did not experience any more leaks.

Prior to discovering the grommet (accidently, using the light test method prescribed above)  I had done all other manner of things, the most inconvenient being blue taping the entire windshield surround every 3 days.  I don't have a sunroof, so the windshield was the only source that came to mind.

I wish I had read this post and the post immediately above back when I found my leak on the driver's front floor.  It seems crazy, but now, the first place I look for a leak is the firewall grommet.

Sure enough, I encountered another automobile... a Lincoln in fact, that had the same issue.  Something to check always.
 
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