all warning lights on, read details
08-03-2014, 02:45 PM
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89 300te, 91 300te
all warning lights on, read details
Battery was on its way out, daughter needed to jump start her and hooked up the cables THE WRONG WAY! on the 300TE side. Knew I needed a new battery anyways(under warranty), put it in and car started right up. Problem is that all the warning lights are on, i mean even the parking brake! which i have never used, and voltage in new battery is down to 11 volts with minimal driving. did my daughter fry the alternator, and why are ALL of the lights on. Have 89 to use parts for troubleshoot. Wanted to get opinions first. thank you
08-03-2014, 03:37 PM
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07 E63 + 07 CLK63CAB
Voltage regulator is fried, as for the lights, if the battery is showing 11 volts then either it is not fully charged ( likely so) or it has a dead cell.
Do the alternator first get the system charging, while changing the alt put the new battery on a charger and verify 12.8Volts before putting it back in the car.
Not sure why the lights are on but low voltage does weird things in a Merc.
Do the alternator first get the system charging, while changing the alt put the new battery on a charger and verify 12.8Volts before putting it back in the car.
Not sure why the lights are on but low voltage does weird things in a Merc.
08-03-2014, 04:40 PM
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89 300te, 91 300te
Voltage regulator is fried, as for the lights, if the battery is showing 11 volts then either it is not fully charged ( likely so) or it has a dead cell.
Do the alternator first get the system charging, while changing the alt put the new battery on a charger and verify 12.8Volts before putting it back in the car.
Not sure why the lights are on but low voltage does weird things in a Merc.
Do the alternator first get the system charging, while changing the alt put the new battery on a charger and verify 12.8Volts before putting it back in the car.
Not sure why the lights are on but low voltage does weird things in a Merc.
08-03-2014, 08:12 PM
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07 E63 + 07 CLK63CAB
I would try the voltage reg first, nothing to lose!
Disconnect all battery sources change out reg then after all is tight replace battery terminal connections after making sure they are clean also.
As stated before make sure it is a Bosch unit or if you are using parts off another then I would just change out the alternator if it was working good before.
Good Luck,
let us know how it works out
Disconnect all battery sources change out reg then after all is tight replace battery terminal connections after making sure they are clean also.
As stated before make sure it is a Bosch unit or if you are using parts off another then I would just change out the alternator if it was working good before.
Good Luck,
let us know how it works out
08-03-2014, 11:38 PM
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89 300te, 91 300te
I would try the voltage reg first, nothing to lose!
Disconnect all battery sources change out reg then after all is tight replace battery terminal connections after making sure they are clean also.
As stated before make sure it is a Bosch unit or if you are using parts off another then I would just change out the alternator if it was working good before.
Good Luck,
let us know how it works out
Disconnect all battery sources change out reg then after all is tight replace battery terminal connections after making sure they are clean also.
As stated before make sure it is a Bosch unit or if you are using parts off another then I would just change out the alternator if it was working good before.
Good Luck,
let us know how it works out
08-04-2014, 12:11 AM
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07 E63 + 07 CLK63CAB
Not familiar with your car but a quick google search shows the voltage reg is integrated into the alternator, looks like about 25 dollars or so. Also it looks like the 89 alt will work on your 91 but that is for you to look at. Searched 91 Mercedes 300te and then select images and scroll down from there,a pic of three alts.
A reman Bosch Alt is about 175 so you have a few options, also depending on your location a auto recycling yard may be a good place to also look.
A reman Bosch Alt is about 175 so you have a few options, also depending on your location a auto recycling yard may be a good place to also look.
08-04-2014, 04:09 PM
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If your car was "jumped" reverse polarity, it is likely that you have blown out the alternator field rectifier stack, if not the main rectifier stack. The VR may be dead as well. The reason all the lights are on is because MB uses a diode "OR" tree to perform a lamp test at engine start up. The diodes "ground" each of the lamps return leads via the field winding in the alternator, thus causing them to light until the alternator field voltage rises to ~ 12 volts (e.g., engine running). If the alternator stacks or the CR are shot, the lights will stay on and the system will not charge. You can verify this be disconnecting the field connection at the alternator (the two small wires). Most of the instrument warning lights should go out. If they don't, the diodes in the instrument cluster may be damaged.
You will also have to replace the OVP relay fuse as well and you really should replace the entire OVP relay as it contains a zener diode (the zener provides the over voltage protection function) that is often damaged by a revser polarity jump. This relay is located close to the battery and the fuse will be on top.
Good luck,
- FD
You will also have to replace the OVP relay fuse as well and you really should replace the entire OVP relay as it contains a zener diode (the zener provides the over voltage protection function) that is often damaged by a revser polarity jump. This relay is located close to the battery and the fuse will be on top.
Good luck,
- FD
