Need electrical help with fog lights
 

Howdy! I have a 2nd gen Fit Sport. I was messing around trying to get the fog lights to stay on with hi beams. Anyhow I ended up shorting something out, not sure how, but now the fog lights don't work.

Here is what I have done so far.

-checked fuse - good
-checked every fuse under dash - all good
-checked power going to the fog light relay under dash - has power.
-checked power at fog lights - no power
-checked fog lights with alternative power - they work
-pulled horn relay and put in fog relay location - doesn't work.
-pulled fog relay and tested myself. Continuity at 173ohms but still allows power to run thru it to light up my test light.
-fog switch turns dash indicator on and off. Functions correctly.

I'm at a loss now. Am I missing something in the circuit? Is there another fog light fuse I'm missing after the relay? Is the relay bad because it is at 173ohms? Thoughts? Advice? Ideas?

Thanks in advance!

Sounds to me like there's another fuse you're missing somewhere, or possibly a fusible link. I'd check the underhood fuses.

173 ohms sounds reasonable for a relay coil. It would be too much for relay contacts when they're closed (and too little for the contacts when they're open).

Right?! That's what I'm thinking too. However, I can't see or know of any other fuses after the relay.

Why?

Sounds like a fuse to me also.

Have you ever driven from las Vegas to Reno in the middle of the night? You would want fogs with hi beams too if you have. I just made that trip and there must have been a thousand Jack rabbits on and by the side of the road during that drive.


I agree, it sounds like a fuse...but where?

Just bought a new relay just to be on the safe side. Still not working after the new fog relay was installed.

Does anyone have a schematic of the fog light circuit?

Anyone? No one has any other ideas or suggestions?

I am not quite understanding what you have already done, but I would be checking for 12 volts across the relay coil when the fog lights are selected to be on. If that is there, then check for +12 on both sides of the relay contact assuming that the relay switches +12v. Otherwise check for -12 v on both sides . I do not have a schematic so I'm not sure which way they do it.

If that is good, then check for 0 ohms between one side of the headlight socket and the negative post of the battery if you previously determined that the relay contacts switch the positive side). If good, then check for 0 ohm between the other side of the fog light socket and the switched relay point.

One of those is going to be open.

https://www.fitfreak.net/forums/atta...ine=1474018090

Maybe this will help

That is a BIG help.

Pull the relay and probe pins 2 and 4 looking for +12 volts. It is hot all the time.

Probe pin 1 to ground with an ohm meter. It should be a few ohms through the lamps.

If good, probe pin 3 and see if it goes to ground when the fog lamps are turned off and on.

You should see one of those 4 pins do not meet what you expect.

Well OP did you get them fixed?

Hey guys, sorry for the slow reply getting back to you. And thank you for all of the help. I just finished moving out of state. I'll have time on Sunday to look at it again. I'll let you know what I find. Thanks again.

So this is what I found...That I need more education and training with electrical issues. :) here is what I found:


"Pull the relay and probe pins 2 and 4 looking for +12 volts. It is hot all the time." ----- ***both pins have power***

"Probe pin 1 to ground with an ohm meter. It should be a few ohms through the lamps." -----*** probed this pin and couldn't get any reading change on ohm meter, but I'm not sure I completely understood what you were wanting me to do***

"If good, probe pin 3 and see if it goes to ground when the fog lamps are turned off and on." -----*** probed and found voltage change when turning fog lights on and off.***

From what I can see and understand, the port that the relay goes into has power on 2 of the 4 pins. To me one of the ports switches to ground when the fog light switch is turned on and off via voltage meter going from 10v to nothing and back. Test light still shows no power to plug right behind fog light bulb.

Didn't fully understand check pin 1 to ground thru the lamps part. I put the meter on pin 1 and a ground and found no change in ohms with lights on or off or if I had the meter touching anything. It read 1ohm the whole time

OK, On pin 1 there should be +12 with the relay installed and the the lights turned on. It is difficult to check that +12 with the relay installed. I am assuming that +12 is there because you checked all of the other pins and swapped the relay. So what I asked you to do is check the circuit between Pin 1 and through the lights to ground with an ohm meter.

Connect one lead to relay pin 1 and the other lead on a good ground. Usualiy just connect to anything metal on the engine for the ground side. The ohm meter should read a few ohms through through the wires and lamps to ground.

One thing I usually do when attaching the meter is to connect the ground side to something on the engine and then temporarily put the other lead to something else that is grounded. Then make sure the the meter reads around 0 ohms. This will tell you that ground side meter lead is making a good connection.

Leave the ground lead attached and move the other lead to relay pin 1. If it still reads open then there is something wrong in the wiring between relay pin 1 and the lamps, or the lamps themselves, or the wiring between the lamps and ground.

I have attached pics of my findings today. I believe the issue is pin #1 since it has no power, no ground, and no change on the ohm meter when I have one side of the meter grounded and the other on the pin. It just reads 1 ohm.

If the port side of the pin #1 is supposed to be a ground but isn't then that would explain why the relay isn't clicking over. It does click when I add a ground wire to it but nothing if I actually plug it in to the port.

OK, I expected you to see about 3 ohms or so on pin 1 to ground. One ohm tells me that you probably did not have the ohmmeter zeroed or those lights draw a lot more current than I expected. At one ohm there would be a 12 to 14 amp draw which is less than the fuse is rated at. So the fuse would not blow. The one to three difference is unimportant for your diagnosis.

Now I am confused.

It appears that the light circuit from relay pin 1 through the lights is OK. If you want to check it another way. Put your ohm meter on pin 1 and ground. You should see your 1 ohm reading again. Now with the meter still attached, unplug or remove one light. The ohm meter reading should double. Leave that light unplugged / removed and unplug / remove the second light. The ohm meter reading should go to open or infinity.

If the readings do this this, then that circuit between pin 1 and ground through the lights is OK and we need to go back and rethink this problem.

One other quick thought. I have seen many intermittent fuses that read good and fail when the load is applied. You might want to throw another 20 amp fuse in fuse position 9.