Hot Sr9850

Oct 26, 2008 8 Replies

I have a problem with this relay on a 1988 420 SEL. It is the one of the six in the black main fusebox at the front towards the bumper at the passenger side. I only see that it controls both the front power windows, but maybe something else? I believe there to be a short somewhere I cannot find, I disconnected the positive wires separately from the window motors but it still is warm to touch. Any help in this is appreciated in advance. Regards, Tony Pike.


Take the relay out and swap it with another similar relay... is the condition still the same?

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

If that relay is for windows only... try pulling the window switch out of the wiring harness at the center console. Be very careful to disassemble the center console.

Ashtray out... two screws... pull ashtray unit out... then slip the tray between the ashtray and shifter out... and slide wood console toward front and then upward.

When you pull those switches out of the wiring harness, is that relay still hot?

You know what is wierd... with ignition off, that relay should not be hot... is that what you are saying? Are you able to power the window open and close with ignition off?

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

Ashtray out... two screws... pull ashtray unit out... then slip the tray between the ashtray and shifter out... and slide wood console toward front and then upward.

When you pull those switches out of the wiring harness, is that relay still hot?

You know what is wierd... with ignition off, that relay should not be hot... is that what you are saying? Are you able to power the window open and close with ignition off?

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

There should be 4 rows of relays. From passenger side toward driver's:

  1. Very long box: this is for light bulb monitoring
  2. Medium length: combination relay (turn signal, emergency flasher, rear defogger)
  3. Three cube relays (from back to front): aux fan, air injection, seat adjustment (seat relay is always on though it shouldn't consume much power)
  4. Four cube relays: aux fan preresistor, headlamp cleaning, power window, fuse holder or anti-theft warning

How many relays do you have in each row?

T> I have a problem with this relay on a 1988 420 SEL. It is the one of the

Correction. Power seat relay is on at either ignition on or front door is open.

Power window relay should not be on when ignition is not on. If it is, either the ignition is bad or previous owner changed the wiring.

If the warm-to-touch relay is indeed for the power seats, possibly the door switches are shorted. Note that there are two switches at each front door. IIRC, one is for the interior light/key buzzer and the other is for the seat adjustment. I will try to see the wiring diagram tonight.

Wan-n> There should be 4 rows of relays. From passenger side toward driver's:

Ashtray out... two screws... pull ashtray unit out... then slip the tray between the ashtray and shifter out... and slide wood console toward front and then upward.

When you pull those switches out of the wiring harness, is that relay still hot?

You know what is wierd... with ignition off, that relay should not be hot... is that what you are saying? Are you able to power the window open and close with ignition off?

I would taker that relay apart and see if the internals are shorted... compare the resistance with another identical unit.

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