W203 / C32 AMG Electrical Issue
04-04-2021, 11:21 PM
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C32 AMG
W203 / C32 AMG Electrical Issue
Hey guys!
I could have sworn I've been on here for years already -- I've been slowly restoring a W460 300GD (Gelandewagen) SWB in California for the better part of a decade now... my fault for building from the ground up and formerly owned a nice 300CD as well. In the interim, I've made a glorious mistake -- I bought an AMG from those wonderful Daimler-Chrysler cost-cutting years.
The car in question is "Dolores" (of the Westworld main character -- plain but a monster inside), a 2003 C32 AMG with 195,000 miles on the clock.
As such, I've been fixing her up after a little bit of neglect -- BEHR radiator, water pump, 12 spark plugs, filters, battery, catalytic converters, brakes, suspension, CANbus LCD, battery, trim pieces, valve cover seals, a variety of sensors, etc.
When she runs right, this is the most brilliant car I've owned. It's nice having some 320+ horsepower (my supercharger hasn't been rebuilt and I assume my compression is fading from how it came from the dealership) and I'm getting upwards of 23-30 mpg if I'm conservative on the throttle.... and 11.6 when I'm not. But when she doesn't run right... well... the 30+ computers running essentially Windows 95 and a degrading wiring harness are beyond me. Which leads me to post here, after already Googling and searching these forums for a concise answer.
1 time out of 15 right now, I put the key in the ignition, go to crank it and everything dies. No kick from the starter, no dash, no radio, nothing. I've tested my new-ish (April 2020 so one year as of this post) -- it's a 900CCA as recommended and holding a good charge. The RF key was new from the previous owner and I believe they replaced the ignition switch as well. Wasn't an issue for my first 2 years of ownership.
Disconnecting the battery positive cables and jiggering until the chime of the open door came back on solved this issue in the past, but no longer. Not even jumping the car will get the starter to kick over anymore. And weirder, it's coincided with a handful of other odd issues -- unlocking the doors a few nights ago worked but made my right front fog light turn on. Since then, the doors don't lock and that light doesn't work. My right headlight is out (last owner installed aftermarket Xenons into factory housings... I went with reproduction AMG projectors (Depo) and fitted some CANbus LEDs... which worked before all this).
AC randomly stopped working one day and works again now. Auto window up/down also comes and goes. I'm trying to figure out if that block the battery connects to has a blown fuse (no CARFAX accidents or any repairs warranting the blown airbags that would cause the 100A fuse pop), and if it isn't that, I fear it's the front SAM.... which I could pull from a yard somewhere, but I fear it's coded to the VIN, and if not that, has specific bits to the unfortunately rare C32 AMG.
I really, really, really can't afford to shelf out $1600 for anything electronic right now because Covid has ****ed me royally, If it's just the fuse that's in that little plastic breakout box coming from the battery, I could pull one from a yard and do it myself. Anything more engrossing... well.. I need help.
I could have sworn I've been on here for years already -- I've been slowly restoring a W460 300GD (Gelandewagen) SWB in California for the better part of a decade now... my fault for building from the ground up and formerly owned a nice 300CD as well. In the interim, I've made a glorious mistake -- I bought an AMG from those wonderful Daimler-Chrysler cost-cutting years.
The car in question is "Dolores" (of the Westworld main character -- plain but a monster inside), a 2003 C32 AMG with 195,000 miles on the clock.
As such, I've been fixing her up after a little bit of neglect -- BEHR radiator, water pump, 12 spark plugs, filters, battery, catalytic converters, brakes, suspension, CANbus LCD, battery, trim pieces, valve cover seals, a variety of sensors, etc.
When she runs right, this is the most brilliant car I've owned. It's nice having some 320+ horsepower (my supercharger hasn't been rebuilt and I assume my compression is fading from how it came from the dealership) and I'm getting upwards of 23-30 mpg if I'm conservative on the throttle.... and 11.6 when I'm not. But when she doesn't run right... well... the 30+ computers running essentially Windows 95 and a degrading wiring harness are beyond me. Which leads me to post here, after already Googling and searching these forums for a concise answer.
1 time out of 15 right now, I put the key in the ignition, go to crank it and everything dies. No kick from the starter, no dash, no radio, nothing. I've tested my new-ish (April 2020 so one year as of this post) -- it's a 900CCA as recommended and holding a good charge. The RF key was new from the previous owner and I believe they replaced the ignition switch as well. Wasn't an issue for my first 2 years of ownership.
Disconnecting the battery positive cables and jiggering until the chime of the open door came back on solved this issue in the past, but no longer. Not even jumping the car will get the starter to kick over anymore. And weirder, it's coincided with a handful of other odd issues -- unlocking the doors a few nights ago worked but made my right front fog light turn on. Since then, the doors don't lock and that light doesn't work. My right headlight is out (last owner installed aftermarket Xenons into factory housings... I went with reproduction AMG projectors (Depo) and fitted some CANbus LEDs... which worked before all this).
AC randomly stopped working one day and works again now. Auto window up/down also comes and goes. I'm trying to figure out if that block the battery connects to has a blown fuse (no CARFAX accidents or any repairs warranting the blown airbags that would cause the 100A fuse pop), and if it isn't that, I fear it's the front SAM.... which I could pull from a yard somewhere, but I fear it's coded to the VIN, and if not that, has specific bits to the unfortunately rare C32 AMG.
I really, really, really can't afford to shelf out $1600 for anything electronic right now because Covid has ****ed me royally, If it's just the fuse that's in that little plastic breakout box coming from the battery, I could pull one from a yard and do it myself. Anything more engrossing... well.. I need help.
04-11-2021, 04:22 AM
#2
Member
I know you mentioned the battery, but have it checked out anyway. When they start to get weak, it can cause all sorts of completely random havoc.
Did you go with a cheaper conventional lead acid one or an AGM (absorbed glass mat)?
I cheaped out on my '06 C55 and it was fine since it was new, but probably would've caused me issues in a year or two had the car not gotten wrecked. My "new" '05 C55 has a factory AGM and is still going strong.
Did you go with a cheaper conventional lead acid one or an AGM (absorbed glass mat)?
I cheaped out on my '06 C55 and it was fine since it was new, but probably would've caused me issues in a year or two had the car not gotten wrecked. My "new" '05 C55 has a factory AGM and is still going strong.
04-12-2021, 05:04 PM
#3
Senior Member
Sounds like a basic simple issue just overcomplicated by the symptoms.
Why would jiggling the battery cable make it run? Being rhetorical here. It's because you have a bad connection between the battery and the fuse box (also potentially a bad fuse box) or battery and the ground. When you turn the key and lose power is exactly what happens when the 12v battery is poorly connected. You lose your power window auto down/up function when you disconnect the 12v battery. The car has automatic headlights and when set to auto the fog lights turn on at night when unlocking the car from the fob, sounds like one of your fog light bulbs is out.
If I had to work on this car my self, what I would do next is start looking at the cables between the battery and the fuse box (also called SAM, signal acquisition module) and then the fuse box it self. If the cables are good, then you will should take apart the fuse box and look for corrosion or broken leads.
Why would jiggling the battery cable make it run? Being rhetorical here. It's because you have a bad connection between the battery and the fuse box (also potentially a bad fuse box) or battery and the ground. When you turn the key and lose power is exactly what happens when the 12v battery is poorly connected. You lose your power window auto down/up function when you disconnect the 12v battery. The car has automatic headlights and when set to auto the fog lights turn on at night when unlocking the car from the fob, sounds like one of your fog light bulbs is out.
If I had to work on this car my self, what I would do next is start looking at the cables between the battery and the fuse box (also called SAM, signal acquisition module) and then the fuse box it self. If the cables are good, then you will should take apart the fuse box and look for corrosion or broken leads.
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crewchiefpro (04-23-2021)
