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-   -   Electrical Help Needed With Canbus Fog Light Power (http://www.wranglerforum.com/f274/electrical-help-needed-with-canbus-fog-light-power-228283.html)

kenb1023 03-17-2013 02:03 PM

Electrical Help Needed With Canbus Fog Light Power
 
This was posted beofre under a seperate heading but don't think the Subject Line got my point out.

Ok here is what I have. I wired my new after market fogs to the factory wires. When I hit the fog light switch both lights come on for a second then shut off. If I cycle the switch it does it again. Is there a braker in this system and the lights are drawing to much?
I am totally lost. I hooked my meter to the factory fog wires. When I open the door the meter reads 11.8 VDC. It stays that way for a few minutes then drops back to zero. Does anyone have an electrical schematic I can look at? There is just something screwy here. :surrender:

Pushrod 03-17-2013 02:49 PM

Did you connect these in addition to the factory fogs or replace the factory fogs? Canbus may see too much load on the little wires and cut the power off if they were additional to the factory fogs.
When I hooked up the back up spot lights that came in my LoD rear bumper I powered them directly from the battery through a 30 amp 12 volt relay I mounted behind the passenger side tail light. I connected the coil of the relay in parallel with the factory back up light then ran a 12 AWG stranded copper wire through the passenger side frame rail from the battery to the relay then to the lights in the bumper. This way the Canbus is not seeing the additioin of a larger than normal load on the circuit. I have never measured the voltage myself but have read other people troubleshooting and they also were reporting lower than 12 volts, in this case I remember he was working on the headlights.
If you are replacing the factory fogs you may compare the wattage of the new lights in relation to the original.

kenb1023 03-17-2013 03:01 PM

I was replacing the factory fogs. Factory Fogs are 45watts and the new ones are 55 watts. I even tried to hook up a relay and there was not enough power to drive it. I then connected a small LED light (3 Watts) and the barely glowed. The last time a saw something like this was in the Navy. I had a fuse that would read good and even let the voltage potential be read across it but when a load was applied we got nothing. There was just enough vaporized residue inside the fuse to give us the false reading. No one believed it until we cut it open. I can’t even find the fuse or the relay for the fogs.

heinzbean 03-17-2013 03:09 PM

kenb1023
Sounds like the fog-lights are a different wattage to what the system accepts/expects. The electronics in the can bus system are cutting the power electronically to protect the system. (no fuses or breakers). I read about it yesterday but cant find the actual link.

Pushrod 03-17-2013 03:19 PM

Just for a test you may try disconnecting the new lights and reset the computer by disconnecting the battery for a minute. With the battery reconnected check the voltage again then plug in the original lamps to see if they work like they did before the new lights were installed.
Also look in the fuse box by the battery and see which fuse is labeled for the lights if you haven't already. I am at work and the Jeep is at home or I would be more help finding the fuse.

kenb1023 03-17-2013 03:28 PM

Is there a way to reset it? Maybe disconect the battery? Delayed post.

kenb1023 03-17-2013 03:30 PM

Quote:

Originally Posted by Pushrod (Post 3515177)
Just for a test you may try disconnecting the new lights and reset the computer by disconnecting the battery for a minute. With the battery reconnected check the voltage again then plug in the original lamps to see if they work like they did before the new lights were installed.
Also look in the fuse box by the battery and see which fuse is labeled for the lights if you haven't already. I am at work and the Jeep is at home or I would be more help finding the fuse.

Good idea. Can't use the original lights as they went away with the factory bumper. I do have a small 12VDC LED light I can hook up. It only draws 3 watts but it would be a start.

Dick Blonov 03-17-2013 03:33 PM

Do you have an OBD code reader? If not can you use the ignition key method.

«1. To check your Jeep JK Wrangler’s DTC codes, simply insert your key into the ignition, turn it to the ‘ON’ position but do not start the engine. Then, push the key into the ignition cylinder and while holding it in, turn it to the ‘OFF’ position and then back to the ‘ON’ position (3) times straight making sure to end with it in the ‘ON’ position. It is important to keep pushing in on the key to prevent it from catching at the different positions along the way.
2. If you do step #1 correctly, all your dash lights will illuminate and your odometer will show up as a series of (6) dashes. If your Jeep JK Wrangler has logged any DTC’s, they will be displayed soon after the dashes appear. Write down the DTC(s).
3. If your Jeep JK Wrangler has not logged any DTC’s, the dashes on your odometer will be followed by the message ‘-done-’. Turn your key to the ‘OFF’ position and you will in fact be done. »

See if you get a TIPM code. As far as I know, the fog lamps are controlled by the TIPM (no relay, no fuse).

DB

Pushrod 03-17-2013 03:34 PM

I see what you mean about not being able to find the fuse. I was looking at my manual that I loaded into my iPad and it doesn't list fog lights or head light fuses, imagine that.

Lusus_Naturae 03-17-2013 03:44 PM

Not sure if it will help but here's a thread with some explination on how they wired aftermarket fogs - http://www.wranglerforum.com/f33/eas...ts-195851.html

Not sure if it will apply to the 2010 and older group.

kenb1023 03-17-2013 03:48 PM

Ok, realy odd. Did the battery disconect and still same results. Here is the odd part. When the dome lights go out (They are on that timer) the 11.8VDC goes away as well if the fog switch is off.

Pushrod 03-17-2013 04:02 PM

I agree it is a very strange setup. I would like to see a schematic on the system too.

kenb1023 03-17-2013 04:15 PM

Update, there were three codes. All were Fog light related. Low power and over current. Reset the codes and tested the line. Full power is restored. I connected the relay to it and it clicks on and off like a champ. The relay that came with the lights uses a common negative line for the lights and the relay power. Not sure how that would affect the circuit. I am going to look for a relay that has a separate negative for relay control and load power. So far mystery solved.

JPi1 03-17-2013 04:21 PM

Quote:

Originally Posted by kenb1023 (Post 3515342)
Update, there were three codes. All were Fog light related. Low power and over current. Reset the codes and tested the line. Full power is restored. I connected the relay to it and it clicks on and off like a champ. The relay that came with the lights uses a common negative line for the lights and the relay power. Not sure how that would affect the circuit. I am going to look for a relay that has a separate negative for relay control and load power. So far mystery solved.

So you used the relay that came with the new lights along with wiring into the factory fogs? I would suggest: (1)wiring the new lights direct,
(2) using LED lights instead, or (3) get an sPod and stay out of the can bus system completely.

SilverSport 03-17-2013 04:34 PM

1 Attachment(s)
:thumb:

kenb1023 03-17-2013 07:41 PM

Quote:

Originally Posted by JPi1 (Post 3515361)
So you used the relay that came with the new lights along with wiring into the factory fogs? I would suggest: (1)wiring the new lights direct,
(2) using LED lights instead, or (3) get an sPod and stay out of the can bus system completely.

1:Tried the direct method, that is how I got in this mess

2:Would love to have all LEDs. WOuld also like the $$$$$ to get them. Lights came with the bumper so will use them untill I have more $$$$

What is an sPod?

Dick Blonov 03-17-2013 09:25 PM

The TIPM will turn off an output after it detects a number of faults. Only way out of this is a reset. So using a relay is the way to go.

DB

JPi1 03-17-2013 09:29 PM

1 Attachment(s)
Quote:

Originally Posted by kenb1023 (Post 3516220)
1:Tried the direct method, that is how I got in this mess

2:Would love to have all LEDs. WOuld also like the $$$$$ to get them. Lights came with the bumper so will use them untill I have more $$$$

What is an sPod?

Consists of two parts, the switch panel and the power source. Connects directly to the battery, gives you the ability to connect 6 different accessories, each having its own fuse and relay, completely separate from the can bus system.

GeckoJK 03-17-2013 10:17 PM

Factory fog light bulbs are actually only 24 watts on the 2010+

kenb1023 03-18-2013 07:34 AM

Quote:

Originally Posted by SilverSport (Post 3515419)
:thumb:

Thanks for this. Why over complicate a simple electrical circuit?

SilverSport 03-18-2013 07:44 AM

Quote:

Originally Posted by kenb1023 (Post 3518105)
Thanks for this. Why over complicate a simple electrical circuit?

U R Welcome! Complicating electrical circuits seems to be the norm these days.

Lusus_Naturae 04-24-2013 06:32 AM

If only manufacturers would realise we like to modify our vehicles and will just find other ways around it if we need or want to.


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