Hi, I have a 1986 190D 2.5 non turbo.

My rear window defroster is not working, it does not turn on so I will be checking to see if it is getting any power.

I located the 16 amp fuse in the fuse box and replaced it.
I see online that the rear defroster uses a 30 amp metal strip fuse as well.
Is there also a relay?

If there is a relay and a metal strip fuse for the rear window defroster, does anyone know their location?

Thanks.

Have you already tried searching this forum? I'm pretty sure there's more information than you could ever want, or need, right here at the Pelican... Or, look for a schematic online?

I was searching for the 190D specifically, and nothing came up. More info. available now that I took out the 190D portion of the search.

One thing that I can't find anything on is the location of the rear window defroster strip fuse.

Is this any help?
W201 rear window heater switch wiring - plug positions

Thank you. That looks like a great resource. I will have a close look at it.

No problem. Just kinda "popped up" as I searched for W201 as opposed to 190. That diagram is pretty hard to read, I realize. FSM would be your best bet. Gotta be tons more info here on the Pelican. Good luck.

ON my w124, IIRC the GP and the rear defroster use the same fuse and holder.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

OK.

I had some time today to mess with my defroster. I am getting 13 volts to the switch.
I am getting continuity on 12 of the 19 red grid lines going across my rear window.

I get continuity when I test between the two electrical connectors on either side of the rear window.

I do not get power between the two electrical connectors on either side of the rear window. I had someone hold the switch down while the key was engaged but nothing. The switch does not hold into the on position on its own.

Do you think my switch is bad?
I took it out and cleaned it up but it still doesn't work.
Thanks.

Did you find the 30 amp strip fuse? IIRC, the switch activates a relay that feeds power to the defrost grid, through the 30 amp fuse.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

I will look for the 30 amp strip fuse tomorrow. What does IIRC stand for?

I found a strip fuse that is still intact, it was under a black cover.
All fuses are good.
Glove box light, all other accessories work.
I am getting power to the switch.
The switch checks out good with a meter for continuity in on and off positions.
I do not get power between the two electrical connectors on either side of the rear window that connects to the window grid lines.
Could it be because I only get continuity between 12 of my 19 grid lines?
Can't figure this one out.
Thanks.

I just dealt with this this morning. In my case it was the relay timer in the fuse box. Not sure your car has one, but check on that as it is a simple fix if that were your problem

Is the relay timer different than the relay itself?

No, they are the same. The relay timer is really tall probably because it is a relay with a timer built in which turns the defogger off after 30 mins

Great.

I have searched but can't find anything on how to test this relay.
Do you know how to test it?
There is much less info. out there for the 190D

Thanks.