Hi guys , I just replaced the module that controls the daytime running lights which are on all Canadian vehicles on my 96 grand cherokee.Before I replaced it , I had headlights , but no daytime running lights , and no high beams.The way it works is the module takes your high beams , cuts the voltage down to half , thus you have lights on whenever your vehicle is running.Anyway , I recently moved , and now I need an inter provincial inspection , which they will not pass the vehicle if the daytime running lights aren't working.

So , the day after I replaced the module , the daytime running lights are not working , but I do have high beam still.The fuse to control the module is a big 30 amp in the power control box and that fuse is fine.

Anyone have any ideas about what might be causing this problem?I am going to take the module back where I got it , and say it only worked for one day , hopefully it was just a bad module I got.It plugs in right under the fuse box , but I don't believe US vehicles have it as law.

A number of vehicles sold in US market do have the day-time running light feature. However, it is not yet a mandated feature.

From your description, I wonder if there is a relay action involved that is contributing to your problem.

In a standard US configuration, the auxiliary (off road) lights are active only when low beams are active. If you switch on high beams, the aux lights are deactivated.

That action is relay controlled. Perhaps that is where your problem lies????

I checked all the fuses that have anything to do with lighting , and checked the relays that have anything to do with lighting , all are good.as I mentioned my high beams do work now , where the original burned out module that was there had no high beams.The replacement part is in , so I will install it and see if it works , if so then it was a bad module , if not , then there is something else that is not affecting any of the lights other than the DRL.

Put the new module in , DRL worked fine for 2 stops then died , checked all fuses and relays again , all fine.Tried disconnecting the battery and re connect it after 5 minutes , nothing.I then played with the on/off switch and the high beam switch and they worked again , so something must be going in one of the switches, just have to figure out which one and change it.so when it goes off again , will try one switch at a time and see which turns them back on.

Usually, the most problems will come from the high beam multifunction switch. If it hardly ever is used, sometimes the factory applied grease in the contacts will dry up and cause connection problems. Sometimes similar problems occur with the hazard switch function, once you need it, it doesn't work unless you actuate it a bunch of times to cut through the dried up grease.

I've sucessfully taken the switches apart on some vehicles and cleaned out the old grease and Scotchbrite-ed the contacts, and reassembled them with new grease.