Electrical Gremlins / AC noise

elbud72 · July 13, 2006

I have an 03 1500hd 6.0 with 48K miles. Recently I've noticed a cyclical ticking sound every second or so from what sounds like coming from the steering column or just below it. It starts after the truck's been running for 10min or so and I can make it stop by powering the AC off. Turn the AC back on, and it comes back in 5 min or so. Drives me nuts!

More seriously, I've been having "brown outs" while driving. The engine will stumble, all gages go to 0 and then everything restarts like you just started the truck. Even the chimes go off like at startup. The strange part is the radio clock resets to 12:00AM and the CD player shuffles through the CD's in changer. I don't lose the presets though. It's doing this about every other day. I think I have a bad ground or loose wire somewhere but I couldn't find any problems tonight. No codes either.

Anyone have any ideas on either gremlin?

Mike

asilverblazer · July 13, 2006

That second one sounds like the battery connections aren't good. Inside the cable can corrode and you can't see it, even though the ends are clean and tight.

bobcat5544 · July 13, 2006

your 1st problem sounds to be a ac blend or mode actuator problem, when it start to click or thump, change the mode setting to defrost, floor, or vent, and see if it goes away, if it doesn't, then put it back on the setting you had it on and change the temp setting to cold, warm, and hot see if the noise goes way, also when to put it to defrost, vent, and floor make sure air is blowing out of those vent and no other vents. Let me know what happens

For your second problem, you have two things that can cause your problem,

1st if you have a AC Delco battery disconnect the positive battery lead and see if acid is leaking out, also if the label on top of the battery is black then replace it regardless, (gm has two batteries they use one has a sticker that is on top that is black and the other is blue) it will leak if it hasn’t yet, if the battery is not an AC Delco battery, then the other cause would be your ignition switch is going bad

elbud72 · July 17, 2006

Bobcat,

With regards to the AC, the noise does in fact go away when I switch from AC to Defrost. You can hear vents close shut and switch to the upper vents. After changing it back to AC mode and waiting 5 minutes, the noise returns.

Today, when trying to start the truck, it took 3 trys to get it started. Moving the key forward the first 2 times resulted in nothing. No power, no clicking, nothing. I guess it's time for a new ignition module. The truck only has 48K miles. Oh well.

Thanks for the response. What's the solution for the ticking? Is this something I can fix myself or should I have the stealership mess with it?

Thanks

Mike

bobcat5544 · July 17, 2006

Bobcat,

With regards to the AC, the noise does in fact go away when I switch from AC to Defrost. You can hear vents close shut and switch to the upper vents. After changing it back to AC mode and waiting 5 minutes, the noise returns.

Today, when trying to start the truck, it took 3 trys to get it started. Moving the key forward the first 2 times resulted in nothing. No power, no clicking, nothing. I guess it's time for a new ignition module. The truck only has 48K miles. Oh well.

Thanks for the response. What's the solution for the ticking? Is this something I can fix myself or should I have the stealership mess with it?

Thanks

Mike

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The click noise is your hvac mode door actuator. it take about 1 hour to replace let me see if i can get the instructions on is

And on the no start did you check that battery

elbud72 · July 18, 2006

Yes, I took the truck into Auto Zone. Alternator and battery checked out normal. I've had some work done on that ignition switch before and now I notice I can take the key out with the truck running.

I bought the truck used and the dealership said they had ignition/starting problems that were fixed prior to selling it to me. I just think it's strange the radio resets when there's most likely an ignition problem.

bobcat5544 · July 18, 2006

I know it sounds odd that the radio will reset with a bad ignition switch but, it will cause this. What happens is the body control module will lose power that is feed thought the ignition switch causeing the radio to reset. Ihave had it happen on my truck, and I have replaced them on other gm vehicles.

700cc · July 18, 2006

I just traded my 03 Sierra, and I had the same 2 problems you are experiencing. The ticking could never be replicated at the dealership, so I just learned to live with it. My starting problems were caused by a bad hot wire leading to the battery (as others have suggested).

I know it sounds odd that the radio will reset with a bad ignition switch but, it will cause this. What happens is the body control module will lose power that is feed thought the ignition switch causeing the radio to reset. Ihave had it happen on my truck, and I have replaced them on other gm vehicles.

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Argyll · July 18, 2006

The click noise is your hvac mode door actuator. it take about 1 hour to replace let me see if i can get the instructions on is
And on the no start did you check that battery

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I have the EXACT same clicking/ticking noise you have elub72, on my 2003 1500 2wd 5.3L Silverado. If I switch to AC ON, it goes away, but if I cut off the AC and just use vent, it comes back again. Very annoying.

bobcat5544, is it normal for the hvac mode door actuator to make this clicking, or does that mean it's faulty? I assume this is a warranty item. I have about 1 month left on my factory warranty and will take it in for replacement if so.

bobcat5544 · July 18, 2006

The click noise is your hvac mode door actuator. it take about 1 hour to replace let me see if i can get the instructions on is

And on the no start did you check that battery

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I have the EXACT same clicking/ticking noise you have elub72, on my 2003 1500 2wd 5.3L Silverado. If I switch to AC ON, it goes away, but if I cut off the AC and just use vent, it comes back again. Very annoying.

bobcat5544, is it normal for the hvac mode door actuator to make this clicking, or does that mean it's faulty? I assume this is a warrany item. I have about 1 month left on my factory warranty and will take it in for replacement if so.

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It means it is getting bad or completely failed, what happens is there is a little box about 3 x 5 x 1 and inside of it are some small plastic gears, and what will happen is when you flip to a different position it moves a door. well as you can hear the gears wont hold up and begin to strip thus the click sound

jonm126214 · November 13, 2006

Bobcat

In one of your postings you said you might have instructions on changing out the hvac mode door actuator. Were you able to find them? I think I have the same problem. When I have my AC blowing through the vents there is no noise but when I direct the air to the floor or to defrost I get a periodic groaning or grinding sound. It sounds like it is coming from underneath the glove box. The noise appears to stop when I get up to highway speeds and I don't think it is simply the road noise drowning out the AC noise.

Argyll · November 13, 2006

The click noise is your hvac mode door actuator. it take about 1 hour to replace let me see if i can get the instructions on is
And on the no start did you check that battery

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Hey bobcat5544,

Were you ever able to find the instructions/procedure for this (or anyone else have some info)? My defroster is now not working at all. My A/C works, heat works (blower is working fine), but this morning when I pushed the defroster button, the LED light comes on, but the vents don't switch to defrost, air just still blows out of the front dash vents

Figures this would happen when winter is coming, and on a Monday I'm assuming my HVAC door mode actuator has gone out completely? I'm not quite sure where this is located on a '03 Silverado 1500 2wd. And I assume this part can be purchased at any auto parts store? Thanks for any help.

saltwater_addict · November 13, 2006

Same problem here guys clicks until i turn off the ac then i turn it back on and its pretty good for awhile and then starts to click again some instructions to change this would be great seems to be a common thing, the only thing is mine sounded like it was clicking under the hood but it was hard to pinpoint with exhaust and fan etc going can you buy this at the auto parts store easily or is it dealer only and if anyone knows proper procedure please explain

Dux-n-Dawgs · November 16, 2006

Mine started 'ticking' (like a electrical tick) tonight on my way home on the interstate. The kicker for me is I didn't have ANY of the air settings on . The ticking was spaced out about every second and it eventually got to where the intensity changed pitches. When I got home I left the truck running and crawled under the dash and located a little black box just above the gas pedal. This little box has a wheel with slots on it, I'm assuming it's the hvac control box. I tried switching the air controls and it still clicked. I tried pushing the wire connector in 'tighter' and it finally stopped. I'm wondering if mine is a bad connection or a bad unit ?