W126, relays by firewall to what ('87 model)?

[Hit Man X]

On my new (to me) SDL, there are some new relays by the firewall and I'm not sure what they go to.

The first two are to the right of the ABS brain, one's black ~1"x3" and the other ~0.75"x0.75". The smaller of the two also has a 10A fuse.

Anyone out there know what those are for or go to?

[rogerben]

Not sure about your SDL but on my 1990 Coupe the small one with the fuse is the Over Voltage Protection (OVP) relay, and the larger is the fuel pump Relay.

rogerben

Originally Posted by Hit Man X

On my new (to me) SDL, there are some new relays by the firewall and I'm not sure what they go to.

The first two are to the right of the ABS brain, one's black ~1"x3" and the other ~0.75"x0.75". The smaller of the two also has a 10A fuse.

Anyone out there know what those are for or go to?

the small one is the overvoltage relay and the larger black one is the climate control relay, also known as the Klima relay,

[Hit Man X]

What function does the OVP Relay serve? Obviously it's important, but I'm curious.

[sixto]

Cuts voltage to certain system beyond a certain level. A common warning of a bad OVP relay in a Diesel is the ABS light. In fact I've never heard of an ABS light indicating a problem with the ABS in an MB :/ A bad OVP relay also causes problems with cruise control, ACC, EDS, etc. but you might not notice the changes right away. Pull it off and see what happens.

Sixto
95 S420
87 300SDL

[Hit Man X]

Guess it can't hurt anything to try.