I know this topic has been beat to death. My EH/EG Hatch climate control,Defroster, and Fog light Switches do not light up. The "button" lights do come on when pressed for these, it is the back lighting I'm referring to that doesn't work. I do not have this problem with my cluster because I have a separate cluster harness from wire-worx for my S2000 AP1 Cluster. I do not have a dimmer switch issue, my fuses are fine, the bulbs in these are not blown out, My radio/aftermarket CD player works just fine. This leads me to thinking either there's loose wires, but what I really think is, it is likely a ground issue. Many old photo bucket photos no longer work from past threads, Can anyone help me and show me where the grounds are located that may affect this, and how they should be grounded(I've seen the parts diagrams, they don't illustrate very well location in reference to the items around it). Also if anyone can tell me what wire(s) affect the backlighting/power to these parts. Thanks very much. I've had this car worked on for so long, and its almost complete. Any help is appreciated.

PS. the reason I would need to know how they're grounded is because the vehicle was completely disassembled and media blasted, torn apart and re-put back together, so it is not stock in that sense from Honda. Thank you.

Also been a member here since the early 2000s, My old account must've gotten deleted.

 

Check G201 and G401.

G201 Location: Passenger side engine bay behind headlight (ground block)
G401 Location: Drivers side kick panel (ground block)

Could also have a frayed wire? Have you done a continuity check on the BLACK wire (Pin 12) of the AC/Heater Control wire harness to ground? Also, lighting on that harness is RED (Pin 4) and RED/BLACK (Pin 3). I'd check for voltage on those two pins with the lights on.

FWIW I just did the same and took a chassis to the metal to restore it. Had a few grounding locations that got painted over and had to be sanded down to get a good ground.

If you need diagrams from the service manual, I can post them...just ask.

 

Thank you so much. I'll start with those grounding locations. I have not yet tested continuity. Though all of that information is extremely helpful. I have had the Haynes manua for a long timel, and am waiting on the Honda manual to get here soon.I know i'm flat out missing grounds, so ill break out a wire brush, some 10mm bolts, and see if i can't get everything buttoned up and come back if i need more help. Bless you!

 

I could give you a PDF of the service manual for an EG. LMK.

 

I have Power and Illumination! I repaired two grounds and had to ground one that was missing. Did absolutely nothing. I traced wires, there was fraying. Got so tired of the damn thing, that i just cut the Dash harness out that goes behind the speedo down to the fuse panel. Replaced it with another one from eBay. Magical. I have illumination to the Rear defroster button, as well as the Climate control.
Now i have a separate quirk. The blower blows hard. but now, if the rear defroster switch is pushed, it cuts it off (still has illumination), and the blower can't come back on until you shut the car off and restart it lol. That happened with my original trash dash harness as well as the new one. So thats a separate issue going on somewhere else. Likely one of the connectors that goes directly to the fuse box im guessing?

 

The blower resistor unit controls the blower motor speed. Id check that. They are cheap. But if you press the defroster the fan cuts off? Am I understanding you correct?

That's an odd one. Ill take a look at the diagram, but, I am fairly certain those two systems are independent.

 

That's correct, you read that right. the speed of the blower does work with my cc. However, when I hit the rear defroster switch next to the steering wheel, it cuts off the blower. I don't even know how something like that could happen.

 

The blower and defroster are fed from the same single power source. I'd just double check these with a volt meter across the fuse...even though I don't believe any of these are an issue.

• Fuse 41 (Underhood - 80A) - This is the main power fuse. Doubt the issue is here...if this was blown, nothing would work.
• Fuse 39 (Underhood - 50A) - This is the ignition fuse. Doubt the issue is here...again, if this was blown, nothing would power when you turn the key
• Fuse 34 (Underhood - 30A) - This is the rear defroster feed to the . If this fuse isn't blown, then it isn't here.
• Fuse 13 (7.5A Underdash) - This is for the switch to relay, clearly this is working based on what you were saying.

So, im guessing...

1. A failing Rear Defroster relay - My guess is the issues may be here and is where I'd start first. This is in the under hood fuse block C906. Try to have someone turn on the defroster from the inside and listen to the relay to hear it if clicks (or manually test it).
2. A failing Rear Defroster switch - The rear defroster switch is more than a switch, it also contains a timer circuit that triggers the relay mentioned above.

This is an odd issue that I've never seen. The only thing that makes since to me is that the current is all going to the defroster when the switch is turned on, thus starving the blower motor. I am curious is the blower motor has any voltage when the defroster is on.


Looking at this relay diagram from the SM, it does show a path where these could interfere, and it is the ground...

Here are the electrical diagrams for the blower and defroster systems

 

thank you. I'll try these and see what I come up with thank you!

 

So I'm recalling something. Prior to swapping out the upper dash harness and getting illumination, I Dremel sanded a couple of Ground Locations. At G401, I noticed I had two grounds occupying the same location/spot. One was the pack/cluster of grounds, and then a singular ground that I don't know what it was. This couldn't be causing an interference could it?

 

Grounds are grounds so I wouldn't expect that to be the issue.

 

Pretty sure I found the cause of my rear defroster shutting my heater off

 

I'm just going to start over. I found a clean uncut cabin harness. I'm just going to swap it out.

 

Oof....best wishes to you bud. I hope that solves the issues. I hate seeing hacked up wiring...