I have a 1990 190E 2.6 and have been having some strange problems with it as of late. I searched around the forum and found that it is most likely my OVP that needs to be replaced. However, after reading several threads about it and where it should be found I still am unable to find one in my car. I also looked in the owners manual to see if it is mentioned there and I was unable to find it. Does anyone know where the OVP is located in my model? Also is there a good book I can buy that actaully covers all the wiring info as well as parts used in my car (like a Chiltons book)?

The problems that my car has been having are: infrequent stalling when slowing to a stop, ABS malfunction (fires when it is not needed), the engine will sound as if it surges and then the lights will get brighter and my cd-player will turn off. Sometimes this lasts a few seconds or a few minutes. I had my altenator checked as well as my battery. Also I had my ABS sensors cleaned to make sure thats not a cause. Also I noticed another problem lately, my vents are always blowing out hot air, even when the A/C is turned on. Does anyone know what could be causing all these problems?

Thanx,
Joe

Joe, On my 1985 2.3 190e the OVP is located directly behind the battery near the firewall. It is silver in color with a red top that houses a fuse. It's about 2 inches tall and simply plugs into a socket. Beside it is a small black box which is the fuel pump relay (it should have "kickdown" written on the top of it). When you locate the OVP be sure to remove the fuse and check it before replacing the OVP.

A bad OVP in my car caused symptoms similar to what you described. Very easy to replace and can be bought at Fastlane for around $60.00.

Brian

I looked for an OVP as an overvolt protection relay and came up with nothing... is it sometime's called an overload relay or something else?

Thanx,
- Joe

It's an Overvoltage Protection Relay. Check beside the Fuel Pump Relay to see if there is a space where it looks like something should have been plugged into it. Your OVP may by missing...

Brian

Joe, Indeed it is called an Overload Relay on Fastlane. You found the right one (about $49.00). I went to other Mercedes sites and it was called an Overload Protection Relay and Overvoltage Protection Relay. Take your pick. At Fastlane though it is the Overload Relay that you want. By the way, Fastlane had better prices than the other two sites.

There was a thread sometime back on this site that showed a photo of the OVP and Fuel Pump Relay and their location, but I couldn't locate the thread again.

Brian

I searched through the threads and found the thread you are speaking of (http://www.peachparts.com/shopforum/showthread.php?threadid=16730). After looking in the pictures I realized I hand't pulled back a plastic wall and when I did that I found the relay. Mine does not have a red top but the fuse is red. I checked the fuse and it is not broken from what I can tell. I will order a new relay tonight and put it in as as soon as it comes in. Thanx for the help!

Joe

Take off your air cleaner element ( 4 10mm nuts) and have a look at your throttle body. If it is dirty around the top region with possible carbon deposits, then the intake plenum is almost certainly pretty dirty with oily sludge and carbon deposits from your positive crankcase ventilation hose. There is a cool tool that does an outstanding job of cleaning out your throttle body and intake plenum and is better than harsh intake cleaners which could possibly damage an idle speed sensor or air flow sensor. Check out http://www.intakesnake.com

You'll notice your idle will be smooth as silk afterwards.
(Have you replaced your spark plugs latetly??? cheap to do)

Good luck with your 190E brother!!!

Mike McKinney

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1989 300CE - 269,000 km
1994 SL600 - 59,000 km

I've had this experience before but when you said your lights would go brighter at times it sounds very familiar. Your alternator checked good but it might overcharging at times and this will cause various problems like a/c blower motor stopping abs light srs light bad idle etc. Check the alternator again for a prolong period of time and make sure it's not overcharging.