pheme3@gmail.co

Good morning,

I have an 06 Honda Civic LX with 93k miles. I have an electrical issue. I first noticed that the air conditioner had turned off completely, the left turn signal light on the dash was dimly lit. When i applied the left trun signal it cycled at a rapid rate alternating with the DRL light on the instrument cluster. On the way to the dealership i noticed that the AC would come on but would turn off as soon as I applied the left turn signal. The dealer replaced the blower motor on the airconditioner (don't ask me why they thought that was the problem) and claimed that my after market radio was the issue. This didn't make any sense since the radio had been in for over a year. I did however remove the radio completely... same problem. Removed the 7.5 amp fuse disabling the daytime runing lights and that caused some interesting symptoms. The DRLs are off and when I turn the AC on the head lights come on dimly like the DRLs but it's in the outer lense. If I then turn the regular headlights on the AC cut's off again. So I sat there looking at my wiring harness under the dash and noticed something else. The dim headlights go off and on by them selves (keep in mind the fuse is removed and the AC is turned off). They cycle on and off takes a couple minutes for each cycle and when they do I hear a click from under the dash which sounds exactly like the turn signal click. Oh and one more thing, when the DRLs are on the left front turn signal light is on steady but that is the only other light on, when they cycle back off it goes out, so I removed the fender well and unplugged that light bulb thinking there was a short in that wire somewhere. Problem still is the same except now when I engage the left turn signal it acts like a bulb is burned out (cycles rapidly but i don't get the DRL light anymore) however the headlights still cycle on and off by themselves and they come on wn the AC is on and if they cycle on by themselves the AC stops working. I would like to know what is causing all of this. The dealer seems stumped and doesn't want to dig in to it.

If i disconnect all the light bulbs on the left front (Parking light, and both headlamp bulbs) the AC will not come on at all.

I looked at the hvac wiring diagram for my car and after reading the breakdown of the pins on the heater control panel i decided to check for stray voltage on the grounds. Interestingly pin 13 on the connector which is the sensor common ground for what looks like the evaporator temp sensor is a nice even 0 volts untill the headlights are turned on after which it spikes up to 14 volts.

bee guz

You have a body ground problem, find a list of all the body grounds and tigthen an or clean them so they will ground.

I would look for the dash ground first, that one I think is causing all your problems, all the power in the world will not work on a DC system without proper grounds.

pheme3@gmail.co

I guess that I failed to mention that I have already looked on the wiring diagram and discovered that the headlights share a ground with the AC at position 201 & 401. I have already removed, cleaned and reinstalled those as well as the main ground and two grounds under the dash. But thanks anyway for the suggestion. I agree it's definitely indicative of a ground issue.

justinsbg

Just to be clear; has there been any aftermarket installations done to your car? Radio, gauges, ect... Did this just start happening?

justinsbg

Just taking a quick glance at the wiring diagram I noticed something. You said you cleaned G201 & G401. What about G301? I'm assuming you have some sort of manual to know the where some of the ground terminals are, so check out G301 and let me know what you think.

pheme3@gmail.co

I have 8 pages of the hvac wiring diagram in pdf format which helped with locating some of the grounds. Unfortunately I don't have the entire thing and my knowledge of wiring diagrams isn't at the expert level so please don't let me fool you into thinking I have all of this mastered. As for G301, I don't see that one, can you tell me where it is?

As for after market, the stereo is aftermarket. It has been in the car for about a year with no issues. It is wired into the stock stereo plug with an aftermarket connector and wire splices covered in heat shrink tubing. But this is just a radio head unit, there are no extras like amps or subs. I took a good look at that this afternoon and I can't imagine it causing a problem. The wires all ring out and the ground is solid. No wires are hanging or bare and all the connections are clean. I can tell you that with the dash removed and the radio completely disconnected the problem remains the same. When I was checking for stray voltage I had the dash removed and the radio was not installed. The heater control panel was not connected along with all the other little odds and ends like hazard light switch etcetera. I couldn't turn the AC on to verify that it didn't work, but I can say that the headlights still have the strange behavior with all of this disconnected. This evening I was heading home so I put everything back together and suddenly the problem vanished. I drove it for about 15 minutes and everything seemed perfect, headlights worked in conjunction with the AC and everything seemed to be working properly, DRLs, turn signals, etc. I was going about 30 miles per hour when the problem returned. There were no bumps in the road and I wasn't doing anything with any buttons or switches. I heard a very subtle click and all the symptoms returned simultaneously. I hope I'm not over explaining any of this. Just trying to make sure I don't leave anything important out.

If I haven't mentioned it already, I am profoundly greatful for you all for taking the time to help me on this. My local Honda dealership was stumped and gave up.

pheme3@gmail.co

Ok, I see it on the diagram, Looks like 301 comes from the fuse box under the hood. I don't have the page with the picture on it but that shouldn't be too hard to find. I'll take a look at it after work tomorrow and clean that one up as well. I also noticed that I missed G504 from the Heater control panel. I'd imagine that one is located under the dash somewhere but I don't know exactly where. Thanks again, I'll let you know what happens tomorrow.

justinsbg

G301 is the ground for the blower motor relay, left front headlight, left front turn tignal, left front marker light, left front parking light, condensor fan motor, ELD unit, and fan control relay. It looks on the picture like it's under the car on the transmission side frame. Sort of near the headlight assembly.

justinsbg

I can give you a great test to do if you would like to test the ground circuit with yuor multimeter. It's just a little time consuming so if you just want to take the ground off and clean it at this point I understand.

pheme3@gmail.co

Justin, I am still at work so I haven't had an oppertunity to look at G301 yet, but wanted to let you know something that I had left out. I didn't think it was pertinent but something you said stood out to me. When you said that the ground was near or attached to the transmission I remembered that the day i noticed the problem for the first time was the day I had picked up my car from the shop. They had just changed my transmission fluid. I may be jumping the gun but I have a feeling you just hit the jackpot. I'll let you know this evening. Thanks again.

justinsbg

It's near the transmission on the frame, but I wouldn't think someone could disturb the ground just changing the fluid. Keep me posted.

pheme3@gmail.co

Found G301. As soon as I touched it moved. The bolt had backed out and was only a couple turns from falling out all together. After removing and cleaning it I reinstalled it and the problem has vanished. I also checked and the stray voltage disapeared in the connector to the heater control panel. I am confidant that this is resolved. I see what you mean about the placement of the bolt and there is no way it was disturbed during the fluid change. It must have been a coinsidence. At any rate I cannot thank you enough for your time and assistance. I can't believe that the folks at the dealership couldn't figure this out and you managed to do it within a few messages on a forum without even physically seeing my car. So for everyone who took the time to look at this; thank you. Justin, you're a genius. And special thanks to an amazing talented and beautiful woman who managed to appropriate the wiring diagrams I needed for this job.

av911

Glad you found the problem and resolved it.

Harish Sampat

Folks,

Today my daughter called me to inform that her civic-05 (EX model) has similar issue where A/C stops working when headlight is turned on.

The problem has started today. Yesterday we had taken the car to a local auto shop and had freon replaced and also the cabin air filter was replaced.

Do any of you think that yesterday's maintenance work may be related to the A/C problem that she has?

My daughter is at school out of town so unfortunately I cannot take the car back to the mechanic right away. Will have to wait till she is back in town.

I am not a very handyman. What are my options?

Any advice would be very helpful.

Thanks
- Harish

justinsbg

It doesn't sound like the problem you're having is related to the work that was done, but anything is possible. How about checking G301 which is in the same location as the ground I helped the other guy with in this post. It's worth a shot to see if it's loose or corroded.

Javonte Lewis

[QUOTE=pheme3@gmail.co;45614468]Good morning,

I have an 06 Honda Civic LX with 93k miles. I have an electrical issue. I first noticed that the air conditioner had turned off completely, the left turn signal light on the dash was dimly lit. When i applied the left trun signal it cycled at a rapid rate alternating with the DRL light on the instrument cluster. On the way to the dealership i noticed that the AC would come on but would turn off as soon as I applied the left turn signal. The dealer replaced the blower motor on the airconditioner (don't ask me why they thought that was the problem) and claimed that my after market radio was the issue. This didn't make any sense since the radio had been in for over a year. I did however remove the radio completely... same problem. Removed the 7.5 amp fuse disabling the daytime runing lights and that caused some interesting symptoms. The DRLs are off and when I turn the AC on the head lights come on dimly like the DRLs but it's in the outer lense. If I then turn the regular headlights on the AC cut's off again. So I sat there looking at my wiring harness under the dash and noticed something else. The dim headlights go off and on by them selves (keep in mind the fuse is removed and the AC is turned off). They cycle on and off takes a couple minutes for each cycle and when they do I hear a click from under the dash which sounds exactly like the turn signal click. Oh and one more thing, when the DRLs are on the left front turn signal light is on steady but that is the only other light on, when they cycle back off it goes out, so I removed the fender well and unplugged that light bulb thinking there was a short in that wire somewhere. Problem still is the same except now when I engage the left turn signal it acts like a bulb is burned out (cycles rapidly but i don't get the DRL light anymore) however the headlights stillwheee cycle on and off by themselves and they come on wn the AC is on and if they cycle on by themselves the AC stops working. I would like to know what is causing all of this. The dealer seems stumped and doesn't want to dig where did u find it at