So here it is...

I have a 2001 4.7L SLT Quad Cab 4x4

About 2 months ago my driver's side headlight went out. I replaced the bulb and thought that would be the end of that. Then I started noticing that my headlight would work intermittently. Seemed like a loose connection so I went through, double checked all the connections, looked for corroded connectors, etc. put it all back together and still working intermittently. I let the truck just sit with the headlights on and could watch it randomly come on and then off leading me to believe it was not a loose connection anywhere but maybe a bad connection or troubled relay. Long story short I broke out the multimeter and started probing and testing connections to see if perhaps it was relay or something going bad. The hibeams on the driver side work normal and the passenger side headlight works normal on both low and hi beam. So this is specifically the low beam on the driver side that is not getting a good connection. After a few hours of trouble shooting came to the conclusion the low beam connection is good all the way up the the Central Timer Module (CTM) which leads me to believe that the issue is either in the CTM or the headlight switch. Being that it is just the low beam on one side and not the hi beams leads me to believe the headlight switch is good. I'm not a fan of throwing parts and money at a situation and hoping for the best plus I'd like to actually diagnose the issue and determine what exactly the problem is. All I have read about CTM's going bad come with a whole host of issues that I am not experiencing.

Wondering if anyone here can help guide me.

 

It's most likely the CTM.

The switch only provides a "sense" signal to the CTM to turn on both headlights, not just one. CTM failure is common.

There are no relays, it is direct from the CTM to the headlights.

 

Thanks for the input/advice. It appears the CTM is no longer produced so the only option I can find is a used part. I'm not opposed to buying used parts but if this is something that is prone to go out I'm worried another used one will only go out as well eventually. Is there someone who fixes or refurbishes these? Just curious if buying a used one from eBay or a salvage yard is my only option.

 

Rebuilt is fine. If you want you can get yours rebuilt. Search online.

The problem with just swapping it out is the RKE works through it. Your remotes won't work and you'd need to see a dealer to get them reprogrammed.