When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi all, in the picture I have attached the white connector has a thick red positive and thick brown ground wire. I have just been trying to tap into the red wire and it gave a little spark. Now all the functions on the door dosnt work (window button, door handle lighting etc) will this be the sake of just a fuse blown or have I really F**KED it??
Check fuses. If any are blown, replace them and see if things are back to normal. Cycle the key button several times.
Try disconnecting the battery, then reconnecting it.
If none of the above works, a module could be toast, either the one in the photo or another module. Hard to say what can happen when wires are cut in a complex electrical system.
Do you have a Star/DAS/Xentry system? The door module needs to be diagnosed, if a blown fuse is not the problem.
Check fuses. If any are blown, replace them and see if things are back to normal. Cycle the key button several times.
Try disconnecting the battery, then reconnecting it.
If none of the above works, a module could be toast, either the one in the photo or another module. Hard to say what can happen when wires are cut in a complex electrical system.
Do you have a Star/DAS/Xentry system? The door module needs to be diagnosed, if a blown fuse is not the problem.
fair to say I didn't disconnect the battery and I used a flat head screwdriver to try and open the wires to tap into them and obviously when the metal screw driver has touched the wires it sparked. I have swapped the back door modules around to test the one what could be faulty but no it hasn't toast so that's good. Currently testing all the fuses now to see if any are blown.
I took the module out of the door what is not working and put it in the other back door and tested it and the module works in that door. So the module is all good and working. I have tested all other door modules and there working aswell. So I am guessing it's a fuse I just can't seem to find the fuse!... all doors lock and windows open and close apart from this one door.
There is a fuse box under the rear seat. Have you am checked all of these fuses? Have you checked all of the fuses in the car?
Do you have any other electrical problems in the car?
Did you smell smoke or burning plastic when you touched the wire?
Try putting the other door module into the door you are having problems with. Does it work?
Yes all the modules in the car work. I have also checked all the fuses under the back seat with a multimeter and they all seem to be working. No I don't have any other electrical problems in the car only problems is with this certain rear door!... I can't recall smelling any burning when touching the wire just a big spark. I just can't get my head round the problem!! I have checked all the fuses in the passenger side footwell, in the engine bay and under the rear seat and they all seem to be working.
AFAIK the door modules are NOT interchangeable. A166-900-56-12 - which is what you've got there - is the right rear door SAM, so by plugging it in in a different location you can easily make things worse with other components up the chain.
The red wire brings power to the door SAM, so if that is the wire you accidentally shorted, chances are overwhelmingly that that module is OK and that something upstream - whatever provides power to the door SAM - is where you have the problem. I would double-check all fuses, failing which you definitely need to get a schematic so you can find out where that wire connects on the other end, and likely get a get a code scanner or preferably DAS Xentry so you can troubleshoot the issue yourself.
P.S. Did some digging... more info in post below.
Last edited by Diabolis; Jan 20, 2021 at 04:51 PM.
Fuse F57 (30A) in the battery compartment prefuse box provides power to the right rear door SAM. Did you check if you have 12V on that red wire (the one you shorted out) going to the SAM? If you don't, chances are that it is just F57 that popped.
Fuse F57 (30A) in the battery compartment prefuse box provides power to the right rear door SAM. Did you check if you have 12V on that red wire (the one you shorted out) going to the SAM? If you don't, chances are that it is just F57 that popped.
Thankyou for that helpfull information! I shall check that. When you say battary compartment, do you mean the one under the front seat or the one in the boot/trunk?
It's the prefuse box (F33) next to the main battery under the front right seat, which contains fuses F30 to F68. Access by removing front right seat and floor carpet (I don't know if you can get to it if you move the seat all the way up and forward). The F33 box is right alongside the battery under a cover.
It's the prefuse box (F33) next to the main battery under the front right seat, which contains fuses F30 to F68. Access by removing front right seat and floor carpet (I don't know if you can get to it if you move the seat all the way up and forward). The F33 box is right alongside the battery under a cover.
thankyou for that information!! I shall see if I can access the battary/fuse box by not removing the seat if not then I'll remove the seat. I am sure there will be videos or instructions on the Internet somewhere. Thanks for your help.
In that case it most likely is the f57 fuse in the F33 prefuse block next to the battery.
Some of those fuses have silver contacts (they are labelled with and "S" after the current rating) and they need to be replaced with fuses of the same type or you will end up with a bigger problem due to galvanic corrosion between the dissimilar metals. If the fuse just says "30", replace it with a regular 30 amp fuse. If it says "30 S", then you need to get a silver one from MB.
Read the first post and look at the first, second and fifth PDF charts at the URL below. You need to manually copy the link below and replace the "hXXps" part with "https" as I think it is against board rules here to be linking to other MB sites.
In that case it most likely is the f57 fuse in the F33 prefuse block next to the battery.
Some of those fuses have silver contacts (they are labelled with and "S" after the current rating) and they need to be replaced with fuses of the same type or you will end up with a bigger problem due to galvanic corrosion between the dissimilar metals. If the fuse just says "30", replace it with a regular 30 amp fuse. If it says "30 S", then you need to get a silver one from MB.
Read the first post and look at the first, second and fifth PDF charts at the URL below. You need to manually copy the link below and replace the "hXXps" part with "https" as I think it is against board rules here to be linking to other MB sites.
Diabolis, you are a life saver!! Managed to take the seat out and I have located the blown fuse. Thankyou very much!! I will have to go to mercedes tomorrow to get a 30s fuse
Diabolis, you are a life saver!! Managed to take the seat out and I have located the blown fuse. Thankyou very much!! I will have to go to mercedes tomorrow to get a 30s fuse
<snip>
It's my pleasure - glad to hear that's what it was. And, you can definitely try it out with a regular 30A fuse - you just don't want to leave it in there for more than a couple of days.
Diabolis, you are a life saver!! Managed to take the seat out and I have located the blown fuse. Thankyou very much!! I will have to go to mercedes tomorrow to get a 30s fuse
do you remember when you kept sending me PM's because you were trying to retrofit ambient lighting in your truck as I did and you mucked things up and caused this issue? And the advice I told you 2 or 3 times was to check the mother f'ing fuses? Do you also remember when I told you not to PM but to post on the forum so that others could learn (from your mistakes)?
do you remember when you kept sending me PM's because you were trying to retrofit ambient lighting in your truck as I did and you mucked things up and caused this issue? And the advice I told you 2 or 3 times was to check the mother f'ing fuses? Do you also remember when I told you not to PM but to post on the forum so that others could learn (from your mistakes)?
No? Was that just me? Smh.
I checked all the fuses I thought was in the vehicle! I didn't know there was a fuse box located under the seat next to the battery until doug pointed it out to me.
I checked all the fuses I thought was in the vehicle! I didn't know there was a fuse box located under the seat next to the battery until doug pointed it out to me.
@Shepo08 What is the resolution with your vehicle? Please post the status in exchange for the advice you have received from members. It helps future owners. Thanks.
I checked all the fuses I thought was in the vehicle! I didn't know there was a fuse box located under the seat next to the battery until doug pointed it out to me.
you mean the main fusebox for the whole truck...... Learn the vehicle before you start playing with wiring, especially with what you are trying to do.
@Shepo08 What is the resolution with your vehicle? Please post the status in exchange for the advice you have received from members. It helps future owners. Thanks.
vehicle is now all complete. The problem was fuse F57 (30s amp) located in f33 pre fuse block next to the battery located under the drivers seat (if right hand driver ) or passenger seat if the vehicle is left hand drive. I had to get the fuse from mercedes as I believe you can't buy these fuses else where unless some one can correct me? When I have a little bit of time I will make a thread/post on how to retrofit the ambient lighting and the mistakes I made to prevent others from doing the same.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
