lobosdoc

Hi all - first post on the forums, though I've learned quite a bit over the last couple years referencing other's posts, and appreciate the resource tremendously. I have a problem I've been working on the last couple days, but I'm getting ready to throw in the towel, as I can't seem to figure it out. I have a 2010 GL350, basically stock, though there was an aftermarket HID headlight upgrade present when I bought it, and the stereo was also replaced with a newer unit. I have had no electrical problems of any kind for the last two years.
A few days back, the electrical system in the car went crazy. Horn was going off, front lights flashing (probably for a while as I was inside a restaurant and a waiter came looking for me to say it had been alarming for a long time and he was afraid the battery would die). I was confused, as I hate the alarm, so I used the keyfob (long press on unlock) to disable it a long time ago. I had to unlock the door manually, as my keyless entry wasn’t working to deactivate alarm or open doors, and the dash showed loss of multiple systems. Horn kept going off, but intermittently – it would stop periodically, though lights kept flashing, but then start going off again - even when I inserted the key and started the car. Low beam headlights were blinking continuously, regardless of headlight switch position, even with car running. I went through the vehicle, and found that the rear SAM had gotten wet with rain coming in the tail light. I removed it, dissembled it, and found no sign of corrosion or damage, so I dried it well overnight, reassembled it, and put it back in. Voila – everything seemed to be working. I don’t have a STAR, but I have access to a Autel Maxicom via my Uncle, so I hooked it up, and saw stored, but no new errors related to the rear SAM. Everything seemed to be working fine, with one exception.
The low beam headlights (both sides) still blink on and off, even when switched off, as well as the headlight indicator in the dash. In fact, the low beam lights flashed even if I pulled the fuse for the headlights. I disconnected the ballasts for the headlights, which did finally make them stop, but the dash light still blinks when I turn on the switch, which suggests to me it’s not related to the headlights themselves, though I didn’t disconnect the indicators, or running lamps (all of which work fine). I interrogated both rear and front SAM, and get no errors, except when I disconnect the headlights, at which point front SAM reports an open circuit or short. “Component E1e2 (Left low beam) is faulty or the line to the component has an open circuit.” “Component E2e2 (Right low beam) is faulty or the line to the component has an open circuit.”
Main battery was being drained, even with low beam headlights unplugged, going from 12.5V to 11.9V overnight (auxiliary battery sits at 13V and doesn’t appear to lose charge), so I thought maybe the battery was shot, but it has held voltage overnight today now that I’ve disconnected it after a recharge, sitting at around 12.4V.
I read that there is an alarm siren component with non-rechargeable batteries (part# 219 820 32 26) that can go bad and make lights wonky, so I’ve searched for it, but I don’t think my car has one – I have a disk horn, but I can’t find the alarm unit that I can see in EPC and WIS for my vehicle – WIS says “left front wheelhouse” but it’s not in either wheel well, nor along the firewall (which is where the disk horn is).
Anyway, I'm very frustrated, and figured it was time to throw out a lifeline - any suggestions or insights would be very appreciated. Thanks,

Eric

kombifan

Is the battery original?

You might not like it but it points towards two things which you’ve mentioned but maybe don’t want to admit.

1. Your Sam and water intrusion. This usually requires replacement.
1a. F battery 🔋 is original, low voltage issues can also cause all strange issues.
2. Aftermarket electrics are notorious for leeching power and gremlins too

lobosdoc

Yeah, I realize the SAM might be bad, just hoping... I don’t see how the rear SAM would create a headlight issue... just weird. I’ll load test the battery - doesn’t look original, but I’ve only had the car 2 years, so I’m not sure how old it is. I can put the original stereo back in, but that also seems unlikely to be related... I’m going to start looking for indie places with a STAR, but I’m in waaay south Texas, so likely not much local. Thanks for your input!

Eric

kombifan

Do you park outside?

Did This issue happen after a lot of rain 🌧 storms?

the sunroof is known to leak into the cabin, right into the passenger footwell where the front Sam is.
Check the carpet there to feel if it’s wet there.

do check the battery though. It’s an easier fix than he Sam

lobosdoc

Yeah, it was during a rainstorm - or just after one anyway. I checked both SAMs - the front looked good, no moisture in the compartment, fuse box checked out o.k., and interrogated the front SAM with the Autel, no errors reported (until I disconnect the headlamps as I mentioned above). Got a load tester, and will check the battery tomorrow morning... I'd much rather it was the battery too... I'm still a little confused about the alarm - I see a lot of posts, mostly in the c-series forum, about a smart siren with emergency back up batteries that can cause problems with the lights when the battery dies. I've seen references to the same siren in the GL series, and I can see the same siren in WIS, but I can't find the stupid thing. I found the disk horn, right on the firewall engine compartment passenger side, but the siren is supposedly in the driver front wheelwell, and I don't see anything there...

kombifan

i haven’t seen the siren 🚨 for a gl. You’ll have to show it to me on the forums. It might be a euro option or a red herring.

Everythinf uou say keeps me coming back to the rear Sam .... if it’s the only thing that got wet it’s probably shorted out internally.

Check wih with a bucket of water on the sunroof and rear both at level and with the car on a hill to see how the water drains away and if it goes to any compartment. If it does, well then you have your answer.

lobosdoc

This is what I was looking for (part #14). I also attached the description, which seems to indicate that it's in the driver front wheelwell...

kombifan

run your vin through datamb to see what options you have.

It it does say not for us models though.

lobosdoc

Thank you! Reading more carefully would have saved me a lot of frustration! Confirmed with DataMB - falls under 494, US version, and therefore doesn't have it... Appreciate it - one less source of problems.

lobosdoc

Alright, so I’m not certain of the cause, which is frustrating, but after clearing the error codes, everything is working - no flashing lights, no battery drain, no error codes... so far, so good...

kombifan

Your 🚘 is


Let's hope it stays better! 👍🏼