gaazmon

So the other day I washed my 08 CLK550 coupe after sometime and when I went to start it and turned to the accessory position I heard the normal click sound of the turn, but also heard a sort of short/spark sound from somewhere and then all the power just died. Couldn't start the car, couldn't lock the doors, the windows wouldn't move in and out when you closed the door. Completely dead. So I disconnected the negative terminal of the battery and let it sit while I looked for leaks. Couldn't see anywhere in the engine bay on top that water got somewhere out of the ordinary. Also, checked the front behind the grille, but doesn't seem anything would cause that over there.

Also, I recently had the rear SAM replaced because the pin on the connector for the fuel pump burned up and had to have the pin and plug repaired (Black wire #3 pin) and it burn and damaged the pin on the SAM so was recommended to replace. Don't know what caused it, but two years ago, I had to have the fuel pump replaced and my indy mentioned the fuse box having to be cleaned up while they did the fuel pump replacement, but never really paid much thought to it back then. Not sure if this has any relation to the first problem (I hadn't washed it since the SAM replacement until now).

The only thing I have noticed is the rubber seal under the roof antenna has really deteriorated from age and sitting out in the sun and noticed a hole with a piece of the rubber now missing. Could it be possible water getting in there can contact somewhere to cause a short? Also, does anyone know of just a replacement gasket/rubber for the antenna? The ones I found online stated only were for W208/W210.

Clk_master

hello, im sorry hearing that from a CLK owner, check the fuse box, there is a Big red fuse maybe is blowed caused the car to shut off completely. if you need more information on fuse layout you should check on the drive side fusebox, there is a paper with fuse layout and description on each.
you shound check fuse number 31,52 and 57.
here is the link where you can find all information on fuse layout.
https://imgvehicle.com/mercedes-benz...-w209/fuse-box
let me know if you need other info

Flame3g

No idea about the short but thinking you will need an antenna base...
https://mbparts.mbusa.com/oem-parts/...bC12OC1nYXM%3D

gaazmon

Sorry have not gotten back. Been some personal things going on. So It happened once again and decided to check on the negative cable for the battery and when I kinda touched it a bit (On the wire jacket of course), I heard a shorting sound. So I replaced the negative cable and no power loss issues since.

However, the car will not run again and it seems to be the same issue as before as the fuel not being delivered to the engine as it starts but then immediately dies. Something interesting, the first time this issue happened before the rear SAM replacement, the alarm siren was very weak when looking and unlocking. Now before the second time this issue of no engine running happened, the remote keyless entry was not working with the RF side (Only worked with IR when pointing right at door handle). Now, the RF has started working again weirdly enough.

gaazmon

So it ended up being the replacement rear SAM failing. Something is causing a short or burning the unit just have to figure out what. My thinking is leading me to the alarm siren since they have rechargeable batteries inside that many times go bad and leak in side causing damage to the electronics and since before both times the units failing there was a sort of alarm system issue.

gaazmon

Car not starting again in just 24 hours

I followed the troubleshooting from Pelican Parts site and jumped the fuel pump relay slot with a 12ga fuse holder and 20A fuse and got her started.

Pelican Parts - Fuel Pump Testing

I then bench tested the fuel pump relay and it's working normally from what I can tell so not sure why it's not starting normally.

gaazmon

So new symptom. The car started fine about 3 times yesterday, but then wouldn't start until leaving it till this morning where it started normally. Also, the following relays feel hot when touching in the rear SAM:

A Fuel pump relay (N10/2kA)
B Relay 2, terminal 15R (N10/2kB)
F Relay 1, terminal 15R (N10/2k)

Also wondering, my C Reserve relay 2 (N10/2kC) is blank, but my D Reserve relay 1 (N10/2k) has a contact bridge relay. Does anyone know what these two slots are for? Can't really find anything online.

gaazmon

Here is a picture of my rear SAM layout.

Only thing I notice also is that most pictures online the #7 fuse is 7.5A, but the W209 diagrams I find say it's 20A (The W203 diagrams though say 7.5A).

gaazmon

After using the fuse holder bypass method and a test light along with a voltmeter, I was able to determine that there is power coming through the plug to the driver side fuel sender (Pin #2 black/green wire). So when playing with the female plug that is connected to the plug, when I pull up a bit on the plug after it's been locked onto the unit, the unit turns on and I can hear the whirring sound, but when I push the plug down, it stops. Also, if I press the plug in one direction it turns on, but when I press in the other direction the unit stops. From what I can tell when looking at the female plug, the only pin that appears to maybe have an issue is the ground output wire plug (Pin #5 brown wire). Also, the plug on the sender seems to have some sort of corrosion or something on the pin #5 ground input.

So I'm gonna go ahead and change out the female side of the plug and see if that works. If it doesn't, then seems to be an issue with the plug on the unit itself, but figure worth the gamble on the female plug before I have to splurge for a new unit. Based on my search, this drivers side unit is the fuel sender with the built in fuel filter while the passenger side unit is the fuel sender with the built in fuel pump (According to my service records the passenger unit was what my indy replaced 2.5 years back).

gaazmon

After replacing the plug and testing the car, seems to be the sender unit that is the issue. I bent the power and ground pins on the unit a little back towards the trunk and it's working fine now (Think it was the power pin because I first bent it forward and it popped my fuel pump fuse), but will be best to change out the unit still.

EDIT: I let my fuel run down to the way bottom where the picture pops up on the instrument cluster of a car next to a gas pump. Now the fuel gauge seems to not be going down (Was working fine after "fixing" the sender) so I think the sediments at the bottom must've moved up. Another user on here who had the same issue recommended a couple of bottles of techron treatment so will try that.

EDIT: Seems to be all fine again the fuel gauge.