txab

what do you guys mean when you say rear socket ? The light socket that holds the bulb. Duh!

I'd re-check all connections, air and electrical. Then disconnect the battery and try again

DAYTIME RUNNING LAMPS (DRL) The daytime running lamps (DRL) will operate when the ignition switch is in the RUN position, for automatic transmissions (A/T), the gear selector is not in the PARK position, the headlamp switch is in the AUTO position, and for manual transmissions (M/T), the park brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate. The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal it will either turn on the DRL or the headlamps for auto headlamp operation. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. The DRL can be manually turned OFF by depressing the AHL/DRL switch in the headlamp switch. The AHL/DRL defeat switch sends a ground signal through the DRL switch signal circuit to the BCM. The BCM then turns OFF the DRL and headlamps switch to manual control. When the AHL/DRL are manually turned OFF at the headlamp switch, the AHL/DRL will default to ON with the next ignition cycle. The DRL are separate lamps independent of the headlamps. With the headlight switch in the AUTO position, the DRL will either be turned ON or OFF, after an approximate 8-second delay depending on whether daylight or low light conditions are sensed. The DRL 10-amp fuse in the underhood fuse block supplies battery positive voltage to the DRL relay switch contacts and relay coil. When the BCM energizes the DRL relay , the DRL receive voltage on the DRL supply voltage circuit. Ground for the DRL is at G100.

During daylight conditions the DRLs shouldn't illuminate at all when unlocking or locking in my experience. When my ambient light sensor failed, my DRLs illuminated during the day as you describe, but also my headlamps were on all the time as well

This happens during daylight? The DRLs remain lit as you descrobe? Are your headlights on all the time during daylight? Sounds like the ambient light sensor is bad, tricking your system to think it's dark

He's already done that Mike.

Tesnoboy picked up on something. You said they flash when lock/unlocking. As he stated only the turn signals flash. The DRL will illuminate when it's dark, but they won't flash. Are you checking the correct bulbs? Lamps are closet to the radiator grille opening.

The DRLs have worked before while you've owned the vehicle? If you're not the original 4114 is the bulb # Make sure your emergency brake isn't applied even just a notch or two. More later...

Check valve is part of the fuel pump assembly in the tank. That's why it's best to replace the complete unit when you have a pump problem

Pull the vacuum line at the FPR, if you have fuel there, replace the regulator. You may also have a fuel check valve bad Checked your fuel filter?

It's not designed to let the main tank get really low then fill it back up. At the predetermined level the rear tank will begin to fill the main tank, then shut off, until the main tank level drops again. The process begins again. It is designed, as it was explained to me, to keep the main tank at a fairly constant level until the aux tank is empty. Another words you're probably not going to see the gauge drop down and then begin to rise. Why are you needing to know the exact point at which the transfer begins to take place? The systems work great, except in the case of a pump failure

This was answered in your other thread. http://www.gm-trucks...dpost&p=1235387 BTW this comes straight from the GM FSM.

Tune has nothing to do with the re-set.

Try doing a little reading. There is an exhaust section. http://www.gm-trucks.com/forums/index.php?showforum=10

Kindly don't tell people to shut up. It kinda rubs people the wrong way sometimes......You've made me decide to leave this thread without helping you. G'bye. BTW, the OP hasn't been here since August 24th, 2010. So doubt he'll be any help

Clear the code and see if it returns

Or connections and grounds

It relocates the filter above the transmission, so it is less likely to have a dirt problem and plug up again

Have you even asked at a parts store? If not start striking matches 214-2081 is what shows for your setup

Not one of the smarter things to do.......

Have you checked to see if the cig. lighter has power. If that fuse is blown, you'll get no communication from the port.

The issue has been fixed. It turned out that it WAS the fan clutch. Engine doesn't get to 230 degrees anymore and the AC is blowing cold while idling. Thanks for all of your input/help. I hope somebody else who has a similar problem can benefit from my learning curve I'm glad you got it fixed. Everything you described pointed you to an airflow problem. Thank goodness you didnt' go the route someone else suggested and dump your A/C refrigerant and re-charge.

Are the condenser and radiator clear of bugs and debris? Plenty of coolant in the system? No air in the system? Your symptoms still make me lean towards airflow problems. Can you hear the fan vary in speed? If the fan still isn't getting loud at some points, it's not running at max RPMs. You stated it's not as loud as it once was. I'm not trying to convince you that is what the problem is, but don't rule it out completely until you look into some other things

Sounds as if you're not moving enough air through the condenser when sitting still. One thing to check is your fan clutch. Make sure it is locking up when it should. If you still have the original factory clutch it's probably due for a change. Do you still hear a good roar from underneath the hood when it's hot? Your fan should definitely be locked up and providing max air. You can also see if your ac clutch is disengaging at idle. Take a look at it see if it's turning. If it's not take something and tap the face of the clutch and see if it pulls in. Of course while you're doing this be careful and watch for all the moving parts on the engine. If it pulls in your clutch air gap may be too wide or you may a have weak AC clutch.