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Weird things going on with our 2007 ML350 since last rain. First I checked the passenger tail light seals, they seem to be good although water got in the back SAM board area, I checked it and it was ok but cleaned with electrical cleaner anyway. I let everything dry out, obviously the battery was dead.
So, after the dry out period , I was able to jump start the vehicle and all seemed to be fine. Started a test drive, could smell burning, not like engine burning, more electrical I think, could not see any smoke but decided to turn around. Noticed there was no satellite signal although the radio would turn on.
Then the other weird thing is the wipers came on even though they were in the off position and air conditioning was turning on and off. Soon as I pulled into the driveway the fan in front of the engine went full force, then I turned the engine off. What caused this? What should I check? Please provide diagrams to if you can. Thanks alot!
Checked every remaining fuse, they look ok, removed and cleaned front SAM board which looked ok anyway, replaced battery with new battery and started vehicle, no burning smell this time, but again, no satellite or radio signal, wipers come on by themselves, no turn signals, SRS and other warnings come on and off. Is there a specific relay or module that I need to replace? In the meantime, I have disconnected the battery and protected terminals and battery cables so there is no drain.
Please help.
Sorry you didn't get a reply to your post. Did you manage to fix it? Sounds like front SAM problem to me.
I did take out the front Sam underneath the passenger seat where the battery is, looked very clean however I did clean it off anyway with electrical cleaner and replaced it. So I am at a loss at this point. Is there any other fuse, module or relay that I might be missing that controls all this?
When the battery was dead, did you just jump start the car and let it charge itself or did you charge the battery with an external charger? If the former, that electrical burning smell may have been your charging system trying to quickly fill a big hole with electrons.
Charge your battery. If it won't take a full charge (like stay reliably at 12.7V all by itself with the engine off) it may be time for a new battery.
Last edited by rapidoxidation; Oct 11, 2024 at 10:26 AM.
This definitely sounds like a classic case of water damage affecting your electrical systems, particularly around the SAM (Signal Acquisition Module). Water ingress can lead to corrosion or create short circuits in sensitive electronic boards, prompting erratic behavior such as spontaneous wiper activation or intermittent A/C operation. The burning smell is concerning and indicates that some components might be overheating due to short circuits or excessive current flow. With the no satellite signal, your infotainment system might also be impaired, possibly from disrupted connections or fried circuitry. To proceed, I'd recommend checking fault codes in the Front SAM module, as this will manage many of the electronics affected. Using a full system scanner like youcanic will be most effective, as it can access all vehicle systems for comprehensive diagnostics. Avoid relying solely on basic OBD2 scanners like the Actron CP9125, which are limited to powertrain issues and may miss other system faults. If you're confident in your DIY skills, do a thorough inspection for any lingering moisture or corrosion in the SAM area. Have you ensured all electrical connectors are tight and free from moisture or debris that might be affecting the SAM module's performance?
Another update. Reconnected the new battery , turned the key to on, hooked up the scanner, started reading codes, then it stopped about 3/4 of the way through and could not read codes any longer like it lost connection. Could not get a connection after trying again. Now I suspect that if I disconnect the battery a gain for a while and then reconnect, it will do the same thing. Any ideas?
I cannot get the scanner to stay connected , it connects at first, then loses connection, not enough time to finish scanning, is that symptom of front SAM also?
Resting voltage is 12.5 and when the car is running 14.4.
Another update, I replaced the front sam board under the passenger seat. Connected up the battery and started the vehicle all seemed okay for the first 15 minutes then the same issues started. The last common denominator with this whole situation is it the radio does power on but I get no satellite signal and I get no radio stations. Could a short in the radio antenna system cause all this? There are multiple boxes related to the radio system and I'm not sure what the check or how to check it. Any help would be much appreciated.
Ok, but from what I have read, and correct me if I am wrong, the rear SAM has nothing to do with the front components, namely the radio signal, wipers, etc. Am I wrong?
Not entirely, but the CAN network reach all modules. For example if Rear SAM boil some water over the Body CAN network, the same disturbed CAN ...disturb the Front SAM, the AC, the Radio, etc. Not to mention about some voltages that's sometimes comes from the back.
Latest update. Replaced Rear SAM board, same issue. If the radio has power but has no satellite or radio reception, what I am I missing? I think I checked all fuses, am I missing one? Is there another module that could be at fault? I am at a complete loss.
Checked all fuses, replaced a couple that were questionable looking, checked with multi meter, all good. After replacing, connected battery, started vehicle and all seemed good, drove at least 15 miles without issues, came home parked the car and locked.
Today, tried to start the vehicle, it started for a second then just shut off, no gears highlighted to show whether it is in Park, Drive or anything. Then I get the message shown in the attached file, then again getting all the other messages SRS, ABS, I AM AT MY WITS END WITH THIS
F***KING VEHICLE!!!! Is it time to trade it in? Not that it is worth anything at this point.
Last edited by schmad1962; Nov 18, 2024 at 06:23 PM.
Everything in the vehicle communicates on the same network. One of those components is likely misbehaving and preventing the others from communicating. You have to identify the problematic one and replace/remove it. If it were me I would start disconnecting non-critical things (Radio, Amp, etc...) one by one until I found the problematic module.
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Electrical mystery
