Hello,

The rear window defogger on my '94 Accord doesn't work. Only the lowest two lines seem to work, but everything else doesn't. I'm guessing that the horizontal lines of the grid are wired in parallel, meaning there must be a break somewhere along one/both vertical lines above the lowest two horizontal lines?

Can someone confirm this? Also, what is a good way to go about diagnosing where exactly the problem might be?


Thanks!!

 

If two lines are defrosting, problem is likely broken horizontal resistance lines on non-working lines.

You can diagnose w/ a Volt-Ohm Meter by moving from voltage feed side along the line taking voltage measurements. You will get 12V until you jump across the defect, where you will see zero volts (ground). Defect can be repaired w/ liquid material laid down w/ a mask to match width of existing lines.

Multiple defects can be determined by measuring linear resistance along "good sections" to confirm single defect w/ power off.

A youtube video on subject:

good luck