Help with some spare wheel well electrical issues
#1
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Help with some spare wheel well electrical issues
First off I’m trying to refurbish a Unicorn. R63 that has seen better days and some neglect. ICarsoft revealed quite a few faults some of which were undervolts on terminal 30, no connection with rear SAM, and no connection to keyless go module.
i checked spare wheel well and found this.
Keyless go connections! Corroded and no module.
i also saw another connector under there
i checked spare wheel well and found this.
Keyless go connections! Corroded and no module.
i also saw another connector under there
#3
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I assume the numerous undervolts are due to a main battery issue but clearly water got into wheel well and killed keyless module and must have messed up a fuse in rear SAM.
I’m pulling the front passenger floor tomorrow to see what’s up in that area. Replace main battery under seat and the aux battery while I’m pulling things apart.
purchased a cut out keyless go module from a 2008 r500 but different part number then original from 2007 but the end connectors are good so I can at least rebuilt the corroded connectors until I can find a same part number keyless go module.
Will i I need to buy a new sam or can I service the one I have?
I’m pulling the front passenger floor tomorrow to see what’s up in that area. Replace main battery under seat and the aux battery while I’m pulling things apart.
purchased a cut out keyless go module from a 2008 r500 but different part number then original from 2007 but the end connectors are good so I can at least rebuilt the corroded connectors until I can find a same part number keyless go module.
Will i I need to buy a new sam or can I service the one I have?
#5
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I'm reviving this thread in the hope that Doctorsti figured out this mystery. I'm also reviving a unicorn, my own R63 with the IDENTICAL problem. So far I've discovered the water and corrosion and the failed Keyless Go. What I haven't found is where the water is coming in from. Doctorsti mentioned the tail lights, how were they sealed off? Where you able to revive your Keyless Go?
#6
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Thread Starter
I'm reviving this thread in the hope that Doctorsti figured out this mystery. I'm also reviving a unicorn, my own R63 with the IDENTICAL problem. So far I've discovered the water and corrosion and the failed Keyless Go. What I haven't found is where the water is coming in from. Doctorsti mentioned the tail lights, how were they sealed off? Where you able to revive your Keyless Go?
regarding the water infiltration I have checked a number of times after rain storms and found nothing in there. I’m washing it today so I’ll spray the hell out of it around the lights lower and check.
fun story my tailgate pump just went out so hatch won’t open so that’s another project I was hoping to avoid. I believe it requires full headliner removal.
I do have the factory service manual on disc if you need anything.
#7
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2006 R500
A little late to help, but I found that the Keyless Go module on the R series will interchange with the ML and GL series of the same year. I don't know if they're compatible across years, haven't found any information one way or another. The Keyless Go connections may appear corroded, but still works fine on my car.
On my R500, I found water intrusion only when the car is facing uphill or flat, so I've taken to just backing it into the driveway to mitigate most of the leakage. However, it seems to be leaking in somewhere around the frame, and tearing off the all the side panels didn't help with locating the source of the water intrusion. It almost definitely was not the taillamps in my experience; it's somewhere on the roof/hatch area. I have since decided to just relocate the Keyless Go module to the shelf where the rear vents sit. The cables are just barely long enough to reach there.
I have removed the tailgate pump before, and as long as the struts are fine, you shouldn't need to remove the headliner. The pump is located right next to the spare tire on the driver side, underneath the dark gray carpet.
The other computer module that could be in there is part number 8YN9526A. The mounting bracket isn't a part of the module itself. It appears to be an antenna amplifier for the phone system. I have removed mine since I have already replaced my head unit with an Android head unit.
On my R500, I found water intrusion only when the car is facing uphill or flat, so I've taken to just backing it into the driveway to mitigate most of the leakage. However, it seems to be leaking in somewhere around the frame, and tearing off the all the side panels didn't help with locating the source of the water intrusion. It almost definitely was not the taillamps in my experience; it's somewhere on the roof/hatch area. I have since decided to just relocate the Keyless Go module to the shelf where the rear vents sit. The cables are just barely long enough to reach there.
I have removed the tailgate pump before, and as long as the struts are fine, you shouldn't need to remove the headliner. The pump is located right next to the spare tire on the driver side, underneath the dark gray carpet.
The other computer module that could be in there is part number 8YN9526A. The mounting bracket isn't a part of the module itself. It appears to be an antenna amplifier for the phone system. I have removed mine since I have already replaced my head unit with an Android head unit.
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#8
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I’m still here and the unicorn is my daily driver however I have not solved the keyless go. I did hunt down a replacement module control unit which wasn’t easy but have yet to solder it in. I’ve been looking for another project during quarantine so may get it wired up. I assume however that it won’t result in a working keyless go without a trip to the dealer for some computer programming.
regarding the water infiltration I have checked a number of times after rain storms and found nothing in there. I’m washing it today so I’ll spray the hell out of it around the lights lower and check.
fun story my tailgate pump just went out so hatch won’t open so that’s another project I was hoping to avoid. I believe it requires full headliner removal.
I do have the factory service manual on disc if you need anything.
regarding the water infiltration I have checked a number of times after rain storms and found nothing in there. I’m washing it today so I’ll spray the hell out of it around the lights lower and check.
fun story my tailgate pump just went out so hatch won’t open so that’s another project I was hoping to avoid. I believe it requires full headliner removal.
I do have the factory service manual on disc if you need anything.
Would you mind sharing what you paid for the service manual and where you bought it?
#9
Member
I found the leak! It took a bit, but by running a garden hose on the roof I discovered that the water is coming UNDER the hatch body seal. It seams that there is supposed to be a sealant between the pinch welded body seam and the rubber gasket. As the water runs down the hatch it enters that gasket, travels over the seam as I’d drops, and flows into the cabin from just above the latch.
Now I need to track down the sealant that will hopefully cut off the leak. Does anyone know what should go in there?
Now I need to track down the sealant that will hopefully cut off the leak. Does anyone know what should go in there?
#10
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2006 R500
Nice that you found it. To keep from having to replace Keyless Go modules, I would just tuck the module in where the rear seat vents are. That way it stays high and dry regardless of whether any future leaks happen.
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focalxplosion (05-17-2020)
#11
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I found the leak! It took a bit, but by running a garden hose on the roof I discovered that the water is coming UNDER the hatch body seal. It seams that there is supposed to be a sealant between the pinch welded body seam and the rubber gasket. As the water runs down the hatch it enters that gasket, travels over the seam as I’d drops, and flows into the cabin from just above the latch.
Now I need to track down the sealant that will hopefully cut off the leak. Does anyone know what should go in there?
Now I need to track down the sealant that will hopefully cut off the leak. Does anyone know what should go in there?
Took a look on Ebay and found that, that would be a cheap replacement. SW and HW numbers match up, which in my experience worked just fine with no reprogramming.
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focalxplosion (05-17-2020)
#12
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https://www.ebay.com/itm/06-12-Merce...MAAOSwXetcbv5-
Took a look on Ebay and found that, that would be a cheap replacement. SW and HW numbers match up, which in my experience worked just fine with no reprogramming.
Took a look on Ebay and found that, that would be a cheap replacement. SW and HW numbers match up, which in my experience worked just fine with no reprogramming.
#13
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2006 R500
My connectors looked almost the same as yours. I just tapped it a few times to get as much out as I could, plugged it in and unplugged it a few times, and it's been working fine so far. I suppose you can get some sort of wire brush in there if need be.
#14
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Connectors - can soak/clean in vinegar for a few minutes and rinse with water, let dry then spray with WD40 before putting things together.
For prevention, look in your first picture (of the spare tire well).
See the 2 rubber grommets in the bottom of the well?
Pull one out - it will never collect water to the level of the electronics again.
(Unless you're of the habit of driving in floods).
I suppose one could drill out the center of the grommet to retain the "factory" essence, but really... No.
For prevention, look in your first picture (of the spare tire well).
See the 2 rubber grommets in the bottom of the well?
Pull one out - it will never collect water to the level of the electronics again.
(Unless you're of the habit of driving in floods).
I suppose one could drill out the center of the grommet to retain the "factory" essence, but really... No.
#15
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https://www.ebay.com/itm/06-12-Merce...MAAOSwXetcbv5-
Took a look on Ebay and found that, that would be a cheap replacement. SW and HW numbers match up, which in my experience worked just fine with no reprogramming.
Took a look on Ebay and found that, that would be a cheap replacement. SW and HW numbers match up, which in my experience worked just fine with no reprogramming.
I found the appropriate 3M sealer that will arrive Tuesday so I can properly seal the rear tailgate. I also freed up the drip gasket in the bottom which should allow future leaks to drain out the bottom. It’s a nifty little grommet with a flap that is supposed to allow the wheel well to drain. Unfortunately over time it can get gummed up and stuck.
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THANK YOU!!! I used vinegar and salt solution to clean the corrosion and then neutralized them with water and baking soda. After cleaning everything up and a little soldering I plugged in the replacement module and it worked!!! Well, except the two driver side door handles which I probably need to replace. I cleaned up the rust and flipped the module 180 degrees to keep the connectors on the high side.
I found the appropriate 3M sealer that will arrive Tuesday so I can properly seal the rear tailgate. I also freed up the drip gasket in the bottom which should allow future leaks to drain out the bottom. It’s a nifty little grommet with a flap that is supposed to allow the wheel well to drain. Unfortunately over time it can get gummed up and stuck.
I found the appropriate 3M sealer that will arrive Tuesday so I can properly seal the rear tailgate. I also freed up the drip gasket in the bottom which should allow future leaks to drain out the bottom. It’s a nifty little grommet with a flap that is supposed to allow the wheel well to drain. Unfortunately over time it can get gummed up and stuck.
#18
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@focalxplosion - Glad it worked for you.
@tsumi - Yes, the flappy grommet is like a solution in search of a problem. It's removed on my car, no way for algae/whatever to plug it up.
MB also uses this kind of thing for drains on the hood vent where the climate control air comes in, and in the drains for the windshield valance.
Even more prone to plugging up (badly) in these locations. It's as though MB assumes:
- All Mercedes-Benz vehicles shall Always be parked in covered parking areas.
- No Mercedes-Benz vehicles should be parked in a park, in the Fall.
I'm joking here - I have no doubt that somewhere buried in maintenance schedules we would find items for checking and clearing blockages in these locations.
@tsumi - Yes, the flappy grommet is like a solution in search of a problem. It's removed on my car, no way for algae/whatever to plug it up.
MB also uses this kind of thing for drains on the hood vent where the climate control air comes in, and in the drains for the windshield valance.
Even more prone to plugging up (badly) in these locations. It's as though MB assumes:
- All Mercedes-Benz vehicles shall Always be parked in covered parking areas.
- No Mercedes-Benz vehicles should be parked in a park, in the Fall.
I'm joking here - I have no doubt that somewhere buried in maintenance schedules we would find items for checking and clearing blockages in these locations.
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focalxplosion (05-26-2020)
#19
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@focalxplosion - Glad it worked for you.
@tsumi - Yes, the flappy grommet is like a solution in search of a problem. It's removed on my car, no way for algae/whatever to plug it up.
MB also uses this kind of thing for drains on the hood vent where the climate control air comes in, and in the drains for the windshield valance.
Even more prone to plugging up (badly) in these locations. It's as though MB assumes:
- All Mercedes-Benz vehicles shall Always be parked in covered parking areas.
- No Mercedes-Benz vehicles should be parked in a park, in the Fall.
I'm joking here - I have no doubt that somewhere buried in maintenance schedules we would find items for checking and clearing blockages in these locations.
@tsumi - Yes, the flappy grommet is like a solution in search of a problem. It's removed on my car, no way for algae/whatever to plug it up.
MB also uses this kind of thing for drains on the hood vent where the climate control air comes in, and in the drains for the windshield valance.
Even more prone to plugging up (badly) in these locations. It's as though MB assumes:
- All Mercedes-Benz vehicles shall Always be parked in covered parking areas.
- No Mercedes-Benz vehicles should be parked in a park, in the Fall.
I'm joking here - I have no doubt that somewhere buried in maintenance schedules we would find items for checking and clearing blockages in these locations.
I put them back but now I can’t seem to figure out whey they are necessary. I might just remove them both. Any thoughts?
#21
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@focalxplosion - Ha! Is really your call, depends on where you want debris to collect.
My suspicion is, these were put in place to trap debris in known locations and avoid it collecting and packing into voids in the body panels where drainage might get further blocked. This would help reduce rust-through warranty claims, since the buildup would retain water - depending on whether body drains worked for all the hidden places or allow stuff to collect (especially of concern if your roads get salted).
I contrast it with a Mk4 VW of mine, these cars had an Excellent 12 year rust-through warranty.
But, they had issue of dirt collecting behind the front inner fender against the cab and fender.
To their credit, VW replaced many many fenders no charge. No doubt, MB would want to avoid this happening.
My suspicion is, these were put in place to trap debris in known locations and avoid it collecting and packing into voids in the body panels where drainage might get further blocked. This would help reduce rust-through warranty claims, since the buildup would retain water - depending on whether body drains worked for all the hidden places or allow stuff to collect (especially of concern if your roads get salted).
I contrast it with a Mk4 VW of mine, these cars had an Excellent 12 year rust-through warranty.
But, they had issue of dirt collecting behind the front inner fender against the cab and fender.
To their credit, VW replaced many many fenders no charge. No doubt, MB would want to avoid this happening.
#22
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Thread Starter
@focalxplosion - Ha! Is really your call, depends on where you want debris to collect.
My suspicion is, these were put in place to trap debris in known locations and avoid it collecting and packing into voids in the body panels where drainage might get further blocked. This would help reduce rust-through warranty claims, since the buildup would retain water - depending on whether body drains worked for all the hidden places or allow stuff to collect (especially of concern if your roads get salted).
I contrast it with a Mk4 VW of mine, these cars had an Excellent 12 year rust-through warranty.
But, they had issue of dirt collecting behind the front inner fender against the cab and fender.
To their credit, VW replaced many many fenders no charge. No doubt, MB would want to avoid this happening.
My suspicion is, these were put in place to trap debris in known locations and avoid it collecting and packing into voids in the body panels where drainage might get further blocked. This would help reduce rust-through warranty claims, since the buildup would retain water - depending on whether body drains worked for all the hidden places or allow stuff to collect (especially of concern if your roads get salted).
I contrast it with a Mk4 VW of mine, these cars had an Excellent 12 year rust-through warranty.
But, they had issue of dirt collecting behind the front inner fender against the cab and fender.
To their credit, VW replaced many many fenders no charge. No doubt, MB would want to avoid this happening.
#23
Member