Can somebody post or send me a layout of 87 126 relays?

[waybomb]

1987 126 420SEL. Early 1987 model, if that matters.

I need to know which relay controls what. The 6 in the fuse box that are bare metal.

I can't seem to find this in my 126 service CD.

Thank You

[S-Class Guru]

Fred, I have some info; I'll try to help.

I show 6 relays (plus a fuse holder) on the driver side of the fuse box.
They are labeled in my data as follows:
C D
E F
H I
K

Relay D is in the upper right corner of the fuse box (when looking from the front of the car).
They control the following functions:

C = Auxiliary radiator fan
D = Auxiliary radiator fan pre-resistor
E = Electromagnetic clutch of air pump (smog pump)
F = Headlight cleaning system
H = Power seats
I = Power windows
J = Empty
K = Dual fuses for anti-theft alarm

Just to make sure we are on the same page, you might pop out relay I, and see of the power windows quit working.

DG

[waybomb]

Thanks! I think that's it. My windows weren't working, so I swapped H and I, and my seats stopped working.

Also, my aux fan continues to run, and I pulled C or D, forget which one, and the fan stopped.

So I have some bad relays. the car sat for almost two years. Don;t let your car sit for two years, it's not a good thing to do. Everything wokred on this car before I stopped using it. Now I am chasing electrical gremlins.

Another question. Just to the left of these relays are two larger relay black boxes. Below the adjacent black box is a little plug in device that has a diode or resistor in it. What is that for?

[S-Class Guru]

That little diode thingy is called G = diode (seat adjustment).
I have no idea what it does, but maybe it helps with motor reversal as you go backwards/forwards.

If your fans run all the time, do they run in low speed (thru the big resistor) or high speed (loud enough to wake the dead)?

High speed is triggered by the water temp at 105 degrees C. Or if an open circuit is detected (failsafe).

If it's high speed, the water temp sensor switch on the head is probably bad, or the wire has broken. I don't know where the sensor is on the V8, but it will probably be on the head where it can screw into a water jacket. It will have two wires. when it fails or a wire breaks, it turns the fans on high (failsafe design). Maybe that will give you a place to start.

If the fan is running on low speed, removing the D relay should kill it.
This one may be more difficult. It is designed to to turn the fans on low when the AC head pressure is between 15-20 bAR. It is triggered by the pressure switch on the AC accumulator. Maybe that pressure switch is bad? You could unplug it when the ac is not running and see of the fan stops. if so, its a bad switch.

Hope this helps. Pardon the grammer errors, relaxing with a glass of chianti after a hard day - HeHe.

DG