Rear defogger/wiper (1 Viewer)

[Redline91]

Hello I recently got into my rear hatch to try to fix the wiper and defogger. I checked the ground underneath the center console and can confirm I have 12 volts to rear wiper harness. I found the rear wiper relay was scorched so I'm thinking that should fix the wiper???

With the rear defogger I am getting around 1v to each terminal so do I just need to start probing the window and do repair or is the 1v mean I have other issues.

 

[Malleus]

Have you looked at the EWD?

 

[Hudson Bay]

Sounds like you're on the right track with the wiper, if the relay is scorched, replacing it will likely solve that issue. As for the defogger, 1V at the terminals does seem low, which might point to a larger issue. It could be a sign of a bad connection or another component in the circuit failing. Also, check for any signs of burning or damage along the circuit path, as you've already found one issue with the relay, it wouldn't hurt to double-check for others!

 

[effjay80]

The diodes on the board are toast those allow directional voltage to pass.

 

[Redline91]

I did some reading with ewd and also some general reading I measured the terminals connected to be 1v, I think I should disconnect them this morning and get a reading hopefully then see closer to battery voltage since the rear window acts like a heat resistor (duh). The probably have to do window circuit repair I imagine.

The ewd also showed me the relay box for rear window wiper does have the power go through it for on position so I grabbed one of those from cruiser corps. I found a schematic where someone replaced the one module but not the diodes and stuff.

 

[Redline91]

I have 12 volts running at driver side and I have continuity going from driver terminal on window to passenger terminal. and continuity on multiple of the lines between. So the only thing I can think of is bad grounding? I know this circuit according to EWD grounds under center console I checked that. I saw in another thread about the connector in the hatch. I did find some corrosion on the number 6 pin behind the wiper delay box. I believe this is the ground for the rear window. I cleaned it yesterday before I ran out of time. But I was thinking maybe to just jump the window with a battery to test if it is the window versus the circuit. maybe seeing if a test light will light up on the two window terminals also.

 

[ebbs15]

Following... I have an issue with my Defroster as well, haven't dove into it just yet but definitely interested in the trouble shooting you're doing and what you find (ie where I should look for potential issues) thanks for spelling out what you're doing!

 

[Redline91]

Well plugged new wiper relay in it worked for 5 minutes it isn't melted but I'd say maybe a grounding issue since the hatch is having issues, weirdly the lock works great.

 

[Redline91]

I inspected for chaffing at the hatch wiring grommet but wonder if I should jump a ground wire to rule that out.