Inoperable speedometer, ABS & ASR lights on due to "crossed" jumpstart
Thread Starter
Newbie
Joined: Feb 2003
Posts: 13
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From: San Jose, CA
1995 S420 1998 E320 4matic Wagon 1986 300E
Inoperable speedometer, ABS & ASR lights on due to "crossed" jumpstart
Hi, while jumpstarting my '95 S420 at night, I inadvertently "crossed" the jump cable terminals, i.e. clamping the + clamp to the - terminal on the battery and vice versa. Anyway, right after starting up, I found the ASR & ABS lights stay on permanently, and my speedometer no longer works! both the odometer and tripmeter still display fine, but no longer advance, no doubt due to the inoperable speedometer. Everything else electrical is in working order. I would greatly appreciate any pointers. I've check all the fuses/relays and they're all fine. Alternator fully funcitonal. Thanks for your help.
Newbie
Joined: Apr 2004
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It was dark and I made the big mistake to connect the + of the booster to - of the car. Stupidity!
The car runs fine. I think that there is something to do with a relais or a hidden fuse somewhere out of my sight.
In my oppinion when power arrives to the speedometer then everything is fixed.
Another user made the same mistake, I wonder how he solved the problem. I wrote him an e-mail asking for help.
The car runs fine. I think that there is something to do with a relais or a hidden fuse somewhere out of my sight.
In my oppinion when power arrives to the speedometer then everything is fixed.
Another user made the same mistake, I wonder how he solved the problem. I wrote him an e-mail asking for help.
Almost a Member!
Joined: Jan 2004
Posts: 25
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From: Los Angeles
S420
I had the same situation before. I believe there are 3 or 4 fuses need to be change. after that, everything is ok. But, I don't know where is the fuse box. I heard the mechanic told me there are two of them: One is under the hood and the other is in the truck. What I can remember is they change some fuse under the hood. Hope this will help.
Newbie
Joined: Apr 2004
Posts: 8
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Thanks very much for your reply.
I have just replaced all fuses (front and back) with new ones.
Problem still goes on.
No working speedometer gauge, no working fuel comsumption gauge and both ASR & ABS yellow lights on.
All the rest is working 100%
I have just replaced all fuses (front and back) with new ones.
Problem still goes on.
No working speedometer gauge, no working fuel comsumption gauge and both ASR & ABS yellow lights on.
All the rest is working 100%
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Almost a Member!
Joined: Jan 2004
Posts: 25
Likes: 0
From: Los Angeles
S420
I just called my mechanic, he told me when the fuse is changed, everything should be fine. The sppedometer and others should be protected by fuse from electric shock. If the problem still there, most likely is:
1. fuse is not firmly inserted.
2. drive around to see if computer will pick up the new message.
3. did you check out if the fuse you take out is blowed out or OK? If it was blowed out, then a fuse change should work. If not, maybe the system is burned.
good luck
1. fuse is not firmly inserted.
2. drive around to see if computer will pick up the new message.
3. did you check out if the fuse you take out is blowed out or OK? If it was blowed out, then a fuse change should work. If not, maybe the system is burned.
good luck
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Newbie
Joined: Apr 2004
Posts: 5
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I may have a solution...
Open up the black plastic computer housing (4 hex screws) where it says "battery in trunk" and check the 4 or 5 10 amp fuses in the car's computer. When my speedo stopped working it was a 10 amp fuse in the computer. Unfortunately I paid a mech. $60 to put the car on the scanner to find out I needed a $ 0.25 fuse.
"this is the rumored SECRET FUSE BOX everyone keeps talking about"
"this is the rumored SECRET FUSE BOX everyone keeps talking about"
Member
Joined: Dec 2002
Posts: 78
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From: Pittsburgh, USA
1995 S420
The cover on the battery clearly states "Disconnect negative terminal before charging, or jumpstarting, to avoid damage to car's electronic components". Simply put, disconnect the battery when charging, and also disconnect the battery when jumping. I confirmed this with my MB tech, who has experience on MBs for past 35 years. Crossing terminals can prove fatal.
Originally posted by Jer
I am afraid I must concur with vilamoura. Reversing the polarity can do serious damage to the discrete components in these electronic control units.
I am afraid I must concur with vilamoura. Reversing the polarity can do serious damage to the discrete components in these electronic control units.
Newbie
Joined: Jan 2003
Posts: 18
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From: Nantes (France)
W140 S300 TD
There was no intervention on my battery, but sometimes ASR & ABS lights are on. It is coupled to an hard sterring wheel (parametric assistance is out of ordrer) and an unoperating tempomat.
Turning the power off and then on makes everything getting rigth.
MB mech. said a captor seems to be wrong.
I know this is a different problem, but could this one(sorry, I don't know the equivalent for the french word "sonde" (borer?)) be a captor problem ?
Turning the power off and then on makes everything getting rigth.
MB mech. said a captor seems to be wrong.
I know this is a different problem, but could this one(sorry, I don't know the equivalent for the french word "sonde" (borer?)) be a captor problem ?
Member
Joined: May 2002
Posts: 85
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From: Solon, OH
C32AMG
ASR/ABS
My '95 S320 has the same problem - ASR and ABS lights on, and hard steering - turn it off and on again, and the problem disappears. BUT, after a week, the problem will not be cured by turning the ignition on and off - it's a permanent situation. I have an appointment with a mechanic next week (parking the car in the meantime). I'll post the results. He suspects a bad ABS sensor. Says the steering boost is speed sensitive, and if that sensor is bad, could cause the entire problem. 
Newbie
Joined: May 2004
Posts: 1
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ABS light on, Speedometer not functional
Replaced the fuse inside the base module. Speedometer came back on ans the ABS light turned off. Base module is located inside a rectangular box on the right rear side of the engine room. Open the cover of the rectangular box and you wil see 3 fuses at the very rear of the box. They have red colored fuse.
Newbie
Joined: Feb 2014
Posts: 1
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1992 Mercedes Benz 500sel
I have this same problem with my 1992 Mercedes Bez 500sel as of today ... wasn't having these problems until I gave my car a jump single handled ... Checked fuses THERE OK... I don't know what needs to be done COULD SOMEONE OFFER HELP I WOULD APPRECIATE
Newbie
Joined: Aug 2014
Posts: 4
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S500
Open up the black plastic computer housing (4 hex screws) where it says "battery in trunk" and check the 4 or 5 10 amp fuses in the car's computer. When my speedo stopped working it was a 10 amp fuse in the computer. Unfortunately I paid a mech. $60 to put the car on the scanner to find out I needed a $ 0.25 fuse.
"this is the rumored SECRET FUSE BOX everyone keeps talking about"
"this is the rumored SECRET FUSE BOX everyone keeps talking about"
Last edited by Abrar555; Aug 17, 2014 at 07:46 AM.
MBWorld Fanatic!
Joined: Jun 2010
Posts: 1,246
Likes: 52
From: tennessee
s320
yes on the newer models,the computer box is shaped like a casket.Sometimes the electrical plug on the transmission,will pull ATF in computer box.Clean everything good,and let dry,replace transmission plug.
Newbie
Joined: Aug 2014
Posts: 1
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S320
Inoperable speedometer & Odometer
I have a 1994 S320 with a similar problem. The speedometer and odometer aren't working. The ABS light is one but everything else works. I checked the fuse in the coffin box (there are 2) and one is blown. When I put in a new one, it blows immediately. I also tried changing it with the battery disconnected. Any suggestions?
Newbie
Joined: May 2015
Posts: 1
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1993 300SE Mercedes
Thanks, it works!
y_NY;686550]Open up the black plastic computer housing (4 hex screws) where it says "battery in trunk" and check the 4 or 5 10 amp fuses in the car's computer. When my speedo stopped working it was a 10 amp fuse in the computer. Unfortunately I paid a mech. $60 to put the car on the scanner to find out I needed a $ 0.25 fuse.
"this is the rumored SECRET FUSE BOX everyone keeps talking about"[/QUOTE]
Thanks very much!! I followed your advice and my problems were solved! My speedo is now working and the ABS light doesn't remain on after starting. Now I can take my trip worry free! Thanks again!
"this is the rumored SECRET FUSE BOX everyone keeps talking about"[/QUOTE]
Thanks very much!! I followed your advice and my problems were solved! My speedo is now working and the ABS light doesn't remain on after starting. Now I can take my trip worry free! Thanks again!
Newbie
Joined: Aug 2015
Posts: 2
Likes: 0
1993 Mercedes Benz SL 500
My '95 S320 has the same problem - ASR and ABS lights on, and hard steering - turn it off and on again, and the problem disappears. BUT, after a week, the problem will not be cured by turning the ignition on and off - it's a permanent situation. I have an appointment with a mechanic next week (parking the car in the meantime). I'll post the results. He suspects a bad ABS sensor. Says the steering boost is speed sensitive, and if that sensor is bad, could cause the entire problem.
