Headlight Flicker/Cooling Fan

[bluedragon436]

Now that I've gone to a set of Chinese LED headlight assembly, I notice a flickering in the lights fairly often. After doing a little bit of diagnosing I've figured out it mainly flickers whenever my electric cooling fan cuts on. So right now with having my heat on when I'm driving to and from work, the cooling fan seems to cut on and off pretty often, like almost every time it cuts off, within a minute, it cuts back on... not 100% if it does it with the heat off, will check that today. I've tried replacing the coolant temp sensor multiple times and still have the fan do this, so not sure what else could cause this fan to click on and click off this often.. Was also wondering if folks here think it's more the fan clicking on and off doing the flickering, or a weak alternator?? Even once I put the Hella lights back in, with or without the harness upgrade.. and I pull up to my garage, I can still see the lights flicker, just not as bright/noticeable as the LED's..

[Mayooo]

I would lean towards a weak alternator

[4.3LXJ]

This is the XJ we are talking about, not the Dodge?

[Pinkyman]

Chinese LED headlight assembly

I found your problem...... :smiley-scared003:

[4.3LXJ]

Hey James, I just ran across this. I don't know if it fits your situation, but here it is

http://www.rockridge4wd.com/i-21251500-truck-lite-anti-flicker-adapter-harness-for-jeep-wrangler-jk-07-14-sold-individually.html

[bluedragon436]

This is the XJ we are talking about, not the Dodge?

Yeah, the XJ.. The Dodge has it's own headlight issues from time to time...


I found your problem...... :smiley-scared003:

Yeah I hear ya... that's why I put my Hella H4 housings and upgrade harness back in, to see if that was all it was... but still seems to be there, just not as noticeable with halogen setup compared to the LED

[bluedragon436]

Hey James, I just ran across this. I don't know if it fits your situation, but here it is

http://www.rockridge4wd.com/i-21251500-truck-lite-anti-flicker-adapter-harness-for-jeep-wrangler-jk-07-14-sold-individually.html

Yeah I basically run a setup like those on my Ram to run the HID's, otherwise they'd flicker.. Not sure on the XJ, and why it'd do it though... different setup then the JK's have.. Guess I have a new/upgraded alternator... so might as well throw it in, and see how it goes.. If nothing else, I'll know the XJ will be ready for future electronic additions... I just am hoping I can figure out what is going on... as I'm worried whatever it is, might translate to my LED pods, and any bars I add to the XJ.. and that would suck.. Going to check and see if the interior lights seem to flicker too... in which case, I'll at least know it has nothing to do with the headlight wiring or the cheap LED headlights... then I'll try leaving the cooling fan unplugged (figure it's cool enough outside right now anyways)... and see if that helps any... still won't know if it's the fan causing it, or the alt being weak I guess... hopefully doing the alt will help with the flicker.. otherwise all I can think of is finding another 97+ electric fan in the JY..

[4.3LXJ]

If it just the fan that does that, you could always run the fan continuously on a switch and relay. Wouldn't hurt anything. They do draw quite a bit of power when they start up

[bluedragon436]

If it just the fan that does that, you could always run the fan continuously on a switch and relay. Wouldn't hurt anything. They do draw quite a bit of power when they start up

Yeah that is something I've been kind of considering... As it seems to be the lights flicker when the fan kicks on.. I think I'm mainly trying to figure out why the fan keeps kicking on and off so often... if I could figure that out.... it might help keep from the flickering being so noticeable and annoying..

[4.3LXJ]

The fan should kick on and off. It is just a function of your thermostat opening and closing causing the temp at the sensor to fluctuate

[slvmart]

How about just trying to run the fan off of a independent battery, just as a test. Then turn on the Chinese LED headlights. Do the lights still flicker ?

[XJ Wheeler]

James, are you still running the stock cables? Wondering if old/corroded cables might be hampering power transfer.

Sent via messenger pigeon. I talk, he types.

[bluedragon436]

James, are you still running the stock cables? Wondering if old/corroded cables might be hampering power transfer.

Sent via messenger pigeon. I talk, he types.

Guessing you're referring to the battery cables?? If so, I have replaced all of my cables with some nice beefy lines, in preparation for future alt upgrade, as well as when I did the new upgraded battery install.. Have checked all the negative connections, cleaned them and reinstalled them to see if that would help any with this flicker.. and the closest thing I can come up with is when the A/C condenser fan kicks on, is when it flickers.. so will probably unplug the fan to see if this thought/theory is correct... if so then I'll know it is for sure the fan... then I guess I'll go ahead an install my upgraded alt, to see if that helps any.. I understand the fan is supposed to kick on and off especially when the A/C is turned on.. but this fan seems to cut on and off way too often, like every 30 seconds if not sooner then that... Going to try and swap the fan relay again as well to see if that might make any kind of change...

[XJ Wheeler]

Guessing you're referring to the battery cables?? If so, I have replaced all of my cables with some nice beefy lines, in preparation for future alt upgrade, as well as when I did the new upgraded battery install.. Have checked all the negative connections, cleaned them and reinstalled them to see if that would help any with this flicker.. and the closest thing I can come up with is when the A/C condenser fan kicks on, is when it flickers.. so will probably unplug the fan to see if this thought/theory is correct... if so then I'll know it is for sure the fan... then I guess I'll go ahead an install my upgraded alt, to see if that helps any.. I understand the fan is supposed to kick on and off especially when the A/C is turned on.. but this fan seems to cut on and off way too often, like every 30 seconds if not sooner then that... Going to try and swap the fan relay again as well to see if that might make any kind of change...
Okay, cool. That's one thing checked off. By chance when the fan is cutting off and on is the vent turned on a lower setting? I noticed once I got my a/c working that it would cut off and on often (like every 5-10 seconds) but does a lot better with it turned to high-medium or high. I've heard low freon can also cause this issue. (in general, not necessarily on different vent settings).

Sent via messenger pigeon. I talk, he types.

[bluedragon436]

Okay, cool. That's one thing checked off. By chance when the fan is cutting off and on is the vent turned on a lower setting? I noticed once I got my a/c working that it would cut off and on often (like every 5-10 seconds) but does a lot better with it turned to high-medium or high. I've heard low freon can also cause this issue. (in general, not necessarily on different vent settings).

Sent via messenger pigeon. I talk, he types.

I am going to try and recharge my AC.. but so far I've only really noticed the fan cutting on and off every 10-20 seconds while on heat settings (since it is far too cold for AC right now)... but am thinking about trying to recharge the AC freon anyways, figure can't hurt to try either way.. after that.. not real sure what to do, other then just wiring the fan onto a switch, and bypassing the sensors and such, that cause it to cut on and off constantly whenever the HVAC is turned on, in whatever positions...

[XJ Wheeler]

Is the compressor coming on and cutting off the same time as the fan? I believe it's normal operation is to coincide with the compressor (of course elevated engine temp as well).

Sent via messenger pigeon. I talk, he types.

[Mudderoy]

Now that I've gone to a set of Chinese LED headlight assembly, I notice a flickering in the lights fairly often. After doing a little bit of diagnosing I've figured out it mainly flickers whenever my electric cooling fan cuts on. So right now with having my heat on when I'm driving to and from work, the cooling fan seems to cut on and off pretty often, like almost every time it cuts off, within a minute, it cuts back on... not 100% if it does it with the heat off, will check that today. I've tried replacing the coolant temp sensor multiple times and still have the fan do this, so not sure what else could cause this fan to click on and click off this often.. Was also wondering if folks here think it's more the fan clicking on and off doing the flickering, or a weak alternator?? Even once I put the Hella lights back in, with or without the harness upgrade.. and I pull up to my garage, I can still see the lights flicker, just not as bright/noticeable as the LED's..

A fan sounds like a recipe for failure, but I have no experience with headlights that require them. Voltage drops when current increases. Did you install a new harness? LMC harness for example?

[bluedragon436]

Tony, I originally installed a Putco harness from Amazon.. along with the Hella H4 housings and bulbs... and left that harness installed when I went to these LED headlight housings, figured I'd give them a whirl, price wasn't too bad to try them out... When I first started noticing the flicker, I pulled the harness and still had it, have upgraded to a much better designed harness, very similar to LMC, just doesn't break the bank as much (but not by much).. and still have the flicker... I notice if I turn my HVAC off completely from heat or AC settings, the flicker almost seems to disappear.. so not sure... I'l keep playing with it a bit, and see if once the fan kicks on for engine temps, if it does the constant on/off deal or not... If nothing else, I'm going to try and recharge up my AC, figure might as well top off the XJ, my GF's LJ, and my Ram before the temps start going up outside...

[Mudderoy]

Tony, I originally installed a Putco harness from Amazon.. along with the Hella H4 housings and bulbs... and left that harness installed when I went to these LED headlight housings, figured I'd give them a whirl, price wasn't too bad to try them out... When I first started noticing the flicker, I pulled the harness and still had it, have upgraded to a much better designed harness, very similar to LMC, just doesn't break the bank as much (but not by much).. and still have the flicker... I notice if I turn my HVAC off completely from heat or AC settings, the flicker almost seems to disappear.. so not sure... I'l keep playing with it a bit, and see if once the fan kicks on for engine temps, if it does the constant on/off deal or not... If nothing else, I'm going to try and recharge up my AC, figure might as well top off the XJ, my GF's LJ, and my Ram before the temps start going up outside...

What is the wattage (or current) rating on the harness and what is the same on the headlights?