W124 OVP Replacement - How to?
 

Hi Folks;

Car is a 1989 300E. Sorry if I seem a bit thick but how do replace the OVP? I've certainly found the OVP location and have opened access to it but the metal tabs of the existing OVP relay seem well secured by its plastic bracket. Is there some release tab to allow removal without breaking something? Do you wiggle it up or back or what? Overall, it seems a bit loose but I certainly don't want to regret breaking something by forcing it out.

Thanks for the help.

Paul

If you slide it out, you simply have to unplug it from the harness. It may take some careful prying with a large screw driver to help wiggle the plug loose. There is nothing else holding it in otherwise. The later models W124 had a 7mm bolt securing it, instead of the slip fit.

OVP Removal
 

It's not the pins or harness that I 'm trying to remove or worried about. Its the actual OVP body from whatever bracket that is holding it. I tried to slide the unit back and forth along the OVP's mounted metal bracket/tabs but it did not release. I could not find any screws or bolts. There seems to be a plastic tab that holds the OVP mounting bracket but I couldn't see how this opened up to allow removal of the OVP.

Thanks,
Paul

Yes, there are metal tabs on the bottom front and rear of the OVP. I don't recall the exact procedure, but it involves lifting either the front tab out and then rocking the back one out, or vice versa. It does not pull straight up out of its bracket. One has to rock it out, first one tab then tilt and slip the other tab out.

Do not do this unless the battery is disconnected. Ask me how I know with a big electrical burn.

You using screwdrivers with metal handles? :P:D

Nope...but nonetheless, point still stands. Disconnect battery as there is still current going through it.

when i replaced mine it was just laying in there loose,i saw the metal tabs with holes in them,there was a plastic groove with 1 plastic tab that appeared to hold the ovp in place,but when i tryed to slide it back in place and stick the tab thru the hole it didnt work,so i just left mine sitting there loose.its a bit of a pain wiggleing the connector ends out of the connector,but a little light prying with a small screw driver will do the trick.

As I recall I removed the battery when replacing the OVP relay. That provides much better access and will allow you to see how the OVP relay is secured.

Job done...
 

Thanks for the help.

To remove the OVP relay - you lift the rear most tab upwards and just as it clears its recess, push the relay aftwards so that the front tab clears its recess. There was a bit of resistance but jiggling and some persistance helped free the unit. I pulled the harness off fairly easily and then replaced the OVP relay with the reverse of the above. Nothing broken.

Removing the battery makes access substantially better - I can't see my hands fitting in there while the battery is in place. Also removing the battery probably makes for a safer replacement for any relay just in case it may be always hot (and apparently the OVP unit is).

Thanks again,
Paul