2004 Silverado 1500 - No A/C before and after Blower Resistor & Harness Replacement

[KrazyKen04]

Hey there! After searching for the topic problems and implementing some of the advice, I've come to a place where I can't seem to find help around my unique set of issues. 

 

I've recently acquired a decently maintained '04 Silverado. I immediately ran into the blower problems so many have before me.

 

The specific problem that manifested was two-fold: 

1. No A/C or intermittent A/C (it was intermittent when I bought it)
2. After a day of driving, A/C never worked again and speed 5 stopped working.

 

After research here, I found that the controller and harness often go bad. I replaced those along with the 40A Fuse that blew. My blower then worked on speed 5, but it was never cold. 

 

I then attempted to fix this with a can (specifically AC PRO Refrigerant with the gauge on top). I used the can according to the instructions and it indicated that I need to see a technician. 

 

After the swap and can, a new problem occurred: the blower killed my battery because the fans never turn off, even with the key out.

 

After trickle charging my battery and removing the 40A fuse, I'm back to no cold air and no blower on 5. 

 

Some other research led me to the blend door potentially being stuck or the contacts inside needing cleaning, but I can successfully make the heater blow hot by changing the dials so I don't think that's it (but am up for checking it if you guys think that makes sense). 

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aI'd love some pointers for what direction to go in next.

 

Everything I've found for the 2 problems of no blower on 5 and blower never shutting off leads me to a blower resistor swap. Since I've already done that, where would you guys go next with it?

 

I'm in Texas and am not looking forward to trucking around without A/C ha!

 

Thanks ahead of time for any help, I'm pretty stuck right now and am fairly new to working on Silverados. 

 

EDIT: I have the manual CJ3 system (forgot to include that information previously). 

EDIT 2: The compressor clutch also engages and cycles normally (that was another research path I went down)

[KrazyKen04]

Quick update as I fumble around: 

 

I tried a brand new battery and for whatever reason, the blower now properly shuts itself off when the key is turned off and the 40A fuse is in place.

 

Blower speed 5 also works. 

 

A/C is still non-existent though. 

 

I did go look at the compressor and it appears like it's never engaging now so it seems like that's my next steps forward ?

[carkhz316]

The first thing I would do is to attach a set of AC manifold gauges to verify refrigerant pressures compressor operation. Wild guess, based on your symptoms though, is that you have a leak somewhere.

[KrazyKen04]

I'm going to start there. Will update once I find out. 

 

Thinking back about the compressor, it would cycle normally when I was filling it up with the AC Pro can, so I think the leak theory is pretty spot on. 

 

Appreciate the help! Still learning all this stuff

[carkhz316]

No problem. Keep us updated as to what you find.

[KrazyKen04]

Oh man... I'm an idiot.

 

I clearly had no idea how to deal with this and how to recharge the A/C. It took an AutoZone saint of a manger to come out and show me. 

 

For anyone else dealing with this on this truck:

 

If the A/C is on full blast, the compressor needs to be spinning.

 

If it isn't spinning (likely because the pressure is non-existent on the lines and it needs recharging), the A/C Pro can gauge is always going to show red after your first attempt to fill (the pressure on the line isn't being cycled through so your freon can's gauge is going to get hit with the pressure and show red This confused the hell out of me).

 

As you add freon, the pressure will help the compressor engage and you'll see it start cycling.

 

Pull the trigger on the can between cycles, let go once it cycles and look at your gauge (it's accurate once the compressor engages).

 

Repeat until you get into the green on that can. Your truck should be freezing by the time you start seeing the gauge hit green. 

 

 

[KrazyKen04]

For a complete list of how I attacked the problems I encountered after acquiring the truck (for cheap thank god):

 

1. Problem: A/C Stopped Working on speed 5 and intermittently wouldn't blow cold. Also, the blower stayed on at one point after shutting the truck completely off. 
   • Solution: The Blower Motor Resistor is a common failure. Chevy recommends replacing both the harness (by splicing in a more heavy duty one) AND the BMR. This is not nearly as difficult as it sounds and is all at the foot of the passenger area inside the truck. Tons of youtube vids on this swap. 
   • Bonus Solution if you're lucky: There's a 40A Fuse in your fusebox under the hood. It's towards the top middle (but refer to your fuse box documentation to be sure). I also had to replace this. 
2. Problem: A/C wasn't just blowing now, it was blowing crazy hot. 
   • Solution: The blend door can often get dirty on older models and the contacts in the Blend Door Actuator won't read properly (so the truck's A/C controls don't tell the BDA where to be). You can either replace or just pull it and turn the door yourself (knowing now that your A/C controls can't be adjusted). This is just to the left of the BMR I swapped and held in with two bolts.
   • Since I live in Texas where I only need heat for maybe 3 months a year, I'm leaving it on freezing cold setting and will replace the blend door actuator after I clean it. This was the best youtube vid I found on this topic: https://www.youtube.com/watch?v=Oe9Ms2osURU
3. Problem: Clutch on the compressor never engages, resulting in lukewarm slightly cooled air but definitely not cold. 
   • Solution: You're new old truck's A/C probably needs to be recharged (potentially a leak too though). I've seen it recommended not to use a can of freon, but I ended up using it. See above post for my noobie instructions on that. I find it doubtful you'll be as silly as I was and need them though lol.
4. Final Problem: Dead battery after I had just had it checked at AutoZone. 
   • Solution: My problem ended up being easy: it was stripped, short, old Side Battery Terminal Bolts. About $3 ordered and next day delivered from AutoZone. They just push out of the terminal connectors and you swap in the new ones. They're much longer too and created a rock-solid battery connection. 

All in all, the truck is a joy to work on and it took me this long to fix these routine problems because I didn't understand how that damn can of freon worked lol. But it's Ice Cream Truck freezing cold now  ?

 

Edit: Special note! This is the CJ3 manual A/C. You can identify this by the slider knobs that go up and down for A/C temperature (VS the dials and digital display in the electronic climate version, which I think is the CJ2).