Over-Voltage Protection Relay

[shj]

Can anybody please tell me what the "over-voltage protection relay"does.
Many thanks
Simon
E320 Coupe

 

[Stevie A]

If the car electrics go below a certain voltage around 10 volts, the OVP relay kicks in and prevents damage to sensitive components. This is why often the ABS light comes on when the OVP relay is faulty.

The ABS light comes on when the ABS system is not operating. In the case of a faulty OVP relay, the ABS would be getting no electic power because the OVP relay has cut off the power, hence the ABS light comes on.

 

[shj]

Stevie
Thanks for your help
Simon

 

[tom7035]

If the car electrics go below a certain voltage around 10 volts, the OVP relay kicks in and prevents damage to sensitive components.

Why should it then be called an OVER Voltage Protection relay and not an UNDER Voltage Protection relay?

 

[television]

Car run on a voltage of 13.8v DC, this OVR is mainly there to protect expensive components from breakdown should the voltage for any reason exceed the 13.8v. Should the voltage rise,say when jump starting, or charging, the relay cuts in, dropping the voltage to 7.5 volts. there is a safety fuse on top. hope this helps a little.

malcolm

 

[Myros]

so, does anyone know whether I have one

on a 2/85 500 SL R 107, and if so, where to find the little so and so, as I couldn't see it while doing a handstand in the footwell on Saturday.

 

[yusefu]

Hello Simon,
what Malcolm and Stevie said about over voltage protection relay is right also
OVP relay controls speed that you want the car to drive on.
i bought a used mercedes 190 year 1988 from Germany and shipped to Africa but the OVP relay is missing i have to drive the car from the port to my house
the car was very agressive in speed.It cost about £76:00 including the houseing.now the car is ok.
yusefu

 

[shj]

Hello Yusefu
Thanks for info,it does seem that a dodgy OVR is/can be responsible for a lot of querky behavoir.
Simon

 

[Stevie A]

I agree Tom but what I wrote is what I read about it. It functions though as Malcolm and I have said. In Haynes OVP relay is just called "voltage protection realy".

In my MB manual for my car, it mentions that if "voltage drops below approx 10 volts" then the ABS light comes on and the ABS is off. That's where I got the 10 volts from.

 

[yusefu]

Hello all,
this over voltage protection relay can make you stress,some people in sierra leone call it self bitting relay as it controls self bitting

 

[yusefu]

Hi Sinon,
I knew this name ovp relay when i went to mercedes dealers in croydon. in fact i took with me the housing with part number on it, black plastic sucket cables on it