Almost total exterior light failure, other electrical problems (2007 ML350)
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Junior Member
Joined: Nov 2025
Posts: 15
Likes: 2
2007 ML350
Almost total exterior light failure, other electrical problems (2007 ML350)
I recently purchased this ML350 and have started to dive into its problems. The biggest category is electrical/electronic problems, and they are widespread enough that I suspect there's a faulty control module. I've checked half a dozen components including fuses and relays and bulbs that are all good, so before I go through checking every single one or starting to pull the control modules to narrow down the possible points of failure I thought I would enumerate the problems here and see if someone more experienced can give me an "aha! those are all controlled by the XYZ module". Without further ado...
Every exterior light is dead except the tail lights. That includes the low beams, high beams, turn signals, brake lights, parking lights, etc. The dash display enumerates approximately 14 such failures.
The cruise control works most of the time, but occasionally stops working mid-drive. When it's dead, the dash display shows the failure.
The climate control mostly works, but sometimes the driver side will only vent exterior air, no heat or cooling and no fan control. There's no dash indication for this failure.
The rear hatch power open/close doesn't work, but the "door is open" LED on the open/close switch on the driver's door does work. No dash indication of this problem.
Every exterior light is dead except the tail lights. That includes the low beams, high beams, turn signals, brake lights, parking lights, etc. The dash display enumerates approximately 14 such failures.
The cruise control works most of the time, but occasionally stops working mid-drive. When it's dead, the dash display shows the failure.
The climate control mostly works, but sometimes the driver side will only vent exterior air, no heat or cooling and no fan control. There's no dash indication for this failure.
The rear hatch power open/close doesn't work, but the "door is open" LED on the open/close switch on the driver's door does work. No dash indication of this problem.
Senior Member
Joined: Oct 2023
Posts: 474
Likes: 244
From: New Hampshire
ML 63 AMG
Originally Posted by sparr;[url=tel:9229791
9229791[/url]]I recently purchased this ML350 and have started to dive into its problems. The biggest category is electrical/electronic problems, and they are widespread enough that I suspect there's a faulty control module. I've checked half a dozen components including fuses and relays and bulbs that are all good, so before I go through checking every single one or starting to pull the control modules to narrow down the possible points of failure I thought I would enumerate the problems here and see if someone more experienced can give me an "aha! those are all controlled by the XYZ module". Without further ado...
Every exterior light is dead except the tail lights. That includes the low beams, high beams, turn signals, brake lights, parking lights, etc. The dash display enumerates approximately 14 such failures.
The cruise control works most of the time, but occasionally stops working mid-drive. When it's dead, the dash display shows the failure.
The climate control mostly works, but sometimes the driver side will only vent exterior air, no heat or cooling and no fan control. There's no dash indication for this failure.
The rear hatch power open/close doesn't work, but the "door is open" LED on the open/close switch on the driver's door does work. No dash indication of this problem.
Every exterior light is dead except the tail lights. That includes the low beams, high beams, turn signals, brake lights, parking lights, etc. The dash display enumerates approximately 14 such failures.
The cruise control works most of the time, but occasionally stops working mid-drive. When it's dead, the dash display shows the failure.
The climate control mostly works, but sometimes the driver side will only vent exterior air, no heat or cooling and no fan control. There's no dash indication for this failure.
The rear hatch power open/close doesn't work, but the "door is open" LED on the open/close switch on the driver's door does work. No dash indication of this problem.
Thread Starter
Junior Member
Joined: Nov 2025
Posts: 15
Likes: 2
2007 ML350
Thanks. I tried to edit this thread away and repost in the correct forum, but the moderators seem to have canceled my edit and my repost. I'm trying the repost again now, but I can no longer edit 
