A/C blinking light - over-pressurized? Bad ground?

EDIT #2: Solved, I think. Check my third post below for info. I'm leaving this up for anyone else looking for info in the future.

The A/C in my 2003 access cab, 151K miles, just stopped working. This being August in Phoenix, I need to get it fixed asap. It was working, then it stopped and the interior light just blinks.

Background notes:

• I just had my timing belt, water pump, thermostat, drive belt replaced about 200 miles ago. Suspicious timing?
• I have had my windshield replaced several times, and most recently there is a slight leak on the passenger side. This being Arizona, and I have Weathertech floor mats, I put this issue on the back burner. This is relevant for point #2 below.

I've been doing some research and found the following info:

1. Compressor's ground strap: mine seems to be tight.
2. Windshield leaking water into someplace. I found (and somehow lost) a thread about the windshield leaking water into a switch or something, so it definitely could be that. Things should have dried out since the rain Saturday when it stopped working, but something could be damaged. I can't find the thread that mentioned it, though, to find where or what that location is.
3. A/C relay: I've read about testing by swapping with the horn relay, but I can't find relevant info for 1st gens. Nothing on my fuse block diagram, the Haynes manual, or this forum (that I could find) mentions this relay for our older trucks.
4. Low coolant: Somebody mentioned that an extremely low refrigerant level could cause this, and mentioned the viewport in the front of the truck.

I had noticed bubbles flying around in there, a while ago. I admit I don't know what that viewport is for, or what I should do about it.

In any case, I had some refrigerant on hand, so I figured I'd check that too. Connected the gauge to the low pressure port and the pressure needle pegged ALL THE WAY AROUND. WTF.

I haven't touched the A/C system in a couple of years. I certainly haven't added refrigerant recently. Not sure how it could be radically overpressurized.

Questions

1. Could the timing belt job have caused this?
2. Should I release pressure? Given that it has been in equilibrium for years, seems odd that it is suddenly off the chart.
3. If so, how?

 

Update:

I went back to double check a few things. Noticed that yes, the bolt on the ground strap (I assume) is tight, but the assembly between the ground strap and the compressor is very loose and wobbly. (See diagram.)

In other words, it seems like the bolt may be wrong and doesn't properly clamp it all together tightly? Or is it supposed to wiggle for some reason, to reduce strain from vibrations?!

That doesn't seem right, but the bolt is tight, so not sure?

And still not clear on how that affects the overall system pressure? Must the compressor be running to get an accurate pressure reading?

 

Update: decided to just test something and see: I put a metal binder clip on the bolt head to connect it all together tightly, and the A/C seemed to work. No blinking light for quite a while, i.e., different behavior than earlier.

Solution: Seems indeed to be a bad ground after all.

I added one washer to the bolt and assembly, and that seems to be enough to make it fit tightly. The bolt does look old, and it's short, so...maybe cross-threaded or something?

I'm guessing the mechanic didn't put the right bolt in, or cross-threaded it, when reassembling after the timing belt job. Not sure why it took 200 miles to be an issue, but at least that seems to be the cause.

 

Or....he just wants you to be a repeat customer. Fix one thing, break another.

 

Funny, but I don't think so in this case: this guy is so busy I can't get in to see him when I want to. I beg him for appointments for things I can't handle myself, and I'm lucky if I get in in the next 4-6 weeks.

 

Well then it's probably just an honest mistake. I can only cite my history where for example I've gotten my water pump replaced under warranty and as I'm ready to go home, find one of my CV boot straps missing and spitting grease before I even left the dealership. Having worked underneath my truck a few days before, I knew it was foul play.

 

I mean, I guess that's a good thing? Either you're in a really busy area, or his reputation is great thus extremely sought-out.

Glad you seemingly got it fixed. If I wanted to know the story, I'd get a finishing nail or similar rod, and test the depth of the hole with the bolt removed. If it's way deeper than the hole, maybe wrong fastener? If the hole is shallow, and it's a short bolt already, there's a solid possibility a fastener got snapped off in there already. Or this may just be a case of "the shop lost the shim/washer". Maybe another '03 owner could snap a pic of theirs. I'd expect a hex-head bolt vs. philips screw there, but I dunno.

But yeah, that little ground at 3 o'clock, there's no way in hell that was getting good ground with the fastener that loose.

 

Yeah, getting a photo from another '03 owner would be great: when I looked I thought "that phillips head looks out of place". I'd like to know what it is supposed to be.

 

Here's the parts diagrams for the '03 AC 4WD if you wanna go down that rabbit hole. https://parts.toyota.com/Toyota_2003_Tundra-Access-Cab-Limited-47L-AT-4WD.html

I think you want the Heating & Air Conditioning section specifically: https://parts.toyota.com/Toyota_200...-47L-AT-4WD/Heating-and-Air-Conditioning.html

Probably the Compressor section: https://parts.toyota.com/a/Toyota_2...IR-CONDITIONING---COMPRESSOR/841420-8719.html

I think one of these will be correct, you tell me which? Pretty sure it's the 1st one based on the harness, plate ("88688K" is your "very loose" part, I think?), and the ground strap shown in this exploded. 16¢ for p/n 9331915008 (formerly 93319-15008) and it's labeled as "screw with washer" so maybe your problem was just a lack of washer? I did a deep dive and found this pic btw:

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Or possibly 21¢ with p/n 9006804022 (is the new number, 90068-04022 is old) but it appears it uses a washer also. The wire harness doesn't look right to me but these exploded diagrams are hard as hell to tell sometimes.

 

You're the GOAT, @shifty. The ground wire screw on the compressor is indeed 9331915008. There's always one rouge fastener than decides to poof out of existence...

EDIT
So the dealer didn't have 9331915008 on hand, so I went and grabbed a few different sizes of machine screws at the hardware store.

An M4-.7mm x 8mm screw seems to fit just right. Tightened down the bracket and no play in the ground wire whatsoever. Just a heads up for anyone out there that has fat fingers like me!

 

@shifty` I'm working in this same area for a timing belt change and now trying to remove the compressor and 2 of the bolts won't break loose. I might end up using vice grips as long as I can find the part numbers for the bolts to replace them. One of them is the one with VERY loose on top in the image above, the other smaller one is the one close to the AC line pointing the same direction as the one I just mentioned. any help is appreciated sir.

 

I'd recommend using an impact to try and pop off if it's a standard hex head bolt. Seriously. Use a swivel head if you can't get a good angle on it.

The part numbers should be the same for your '02 as in the diagrams above for the '03. Find the bolt in the exploded diagram above, your part number is the 9XXXX-XXXXX for each bolt you find.

 

yeah, no way anything besides an open end wrench going on these guys. I don't see these bolts in the diagram but I'll study it some more and try to get you a pic. thanks for the quick reply dude

 

The screw in the center of the bracket is stripped, the small bolt on the right is blocked by the AC line which I don't want to evacuate the system if I can avoid it and there's not really a good way to get a socket on the bigger one on the left.

 

Are you using 6-point or 12-point wrenches? It makes a difference.

 

If it helps, here's the EPC for the compressor and surrounding area for a random 2003 AC V8 I was able to track down: https://toyota-usa.epc-data.com/tundra/uck30/3848/electric/8719/?frame_no=5TBRT34172S262383

TBH, I'd be replacing that bracket too. But it's super unclear what the part number is, there are three different ones in the system but it's totally unclear to me which is which, honestly. First one is obviously for lower model trucks, maybe? But I don't understand the "No.1" and "No.2" designations other than seeing it seems to catch a harness/wire differently in the exploded diagram shown.

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only open end wrenches. I'd have to remove that little bracket to get box end on it. my box end are 12pt. I thought about buying ICON brand from HF but still fear it will strip them and I'll have to replace both bolts.

 

I'd try to get the boxhead end of a wrench on it. Open-end is just gonna mangle it.

Actually I'd probably start with removing that bracket, or bending it in such a way that it's out of the way.

I'd start getting that screw out by getting a Dremel with a cutoff wheel and scoring the head of that screw to make it a flathead. Then I'd get a flathead screwdriver that's barely thick enough to fit into the screw slow you made, and tap it in with a hammer. Then try and remove it. If you have a screwdriver with a hole thru it that'll let you insert a bar, that's great. If you have a hand impact driver, that's even better. Basically it's a screwdriver that you hold in place, smack it with a big f'n hammer, and it rotates either clockwise or counterclockwise to forcibly turn a stubborn screw.

 

yeah I was thinking about the Dremel method too on the center screw. I really don't know how to tackle that one by the AC tho, its to narrow to get anything in there unless I can slightly bend the pipe outwards.

thanks again

 

I'm shocked you can't get the closed end of a box-end wrench on that thing. I just tried on mine, and it slipped right on.

If you don't have box-end wrenches, now is a good excuse to go to Harbor Freight or Tractor Supply and buy a kit.

 

I got a set on Sunday. I guess I need to fight with that bracket some more but it definitely isn't slipping right on like yours did. How flexible do you think that AC pipe is? I need to massage it out if I try to get box end on that guy. No way a socket will get in there...

 

Took a few minutes out from grass cutting and tried my 6” pointed vise grips. For me personally if it was my issue, blaster or Kroil would definitely be on that little screw. I would even go a step further and consider removing the fan blades and radiator cover due to hardly any room to turn 2 bolts CCW but mpossibly doable. Had a flash light so I could see if vise grips could fit on bolt heads properly with damn good tightness of grip stremgth. Doable but with patience, especially on bolt by that AC line. Smaller vise grips worked wonders on little ground screw and important screw at that.



Suggest rocking motion also, little CCW, then back CW a little and so on.

 

I'm so pissed. Someone (I think my neighbor) borrowed my long nose VG's and never returned them. I asked him about him, "I dunno, man!"

 

Praying my Son and Sil don’t fight over all the tools I’ve accumulated over 5 decades thanks to Lowes, HF and others

 

Sears! So much of my stuff is probably Craftsman. Especially the old wrenches and stuff.

 

Knipex twin grip pliers may grab that screw. Depending on access.

 

I have no experience with these type of pliers but seem like a better design than channel loks. I saw them on Amazon, kinda pricey tho. Not sure which style I liked better the straight ones or the ones that resemble channel loks. I wasn't sure if you meant I should try these instead of a box end wrench on these bolts or just the center screw on the bracket. I do have some needle nose VG and was going to plan on those first for that, then maybe I can get a better wrench or socket on the 2 stuck bolts

 

Honestly, if you buy the tool on scAmazon, there's no guarantee you're getting an authentic tool these days. Everything on that site is counterfeit nowadays, and they know it, but could give two shits less about us consumers, as long as the money keeps flowing in.

Knipex makes great stuff. And properly constructed JIS screwdrivers will negate stripping screws like that, just hammer them into the screw and twist and that thing won't strip.

 

ok, good news...I went outside a bit ago and tried again. I banged on the bracket a little more with a chisel and hammer and finally got the box end on the bigger bolt and it broke loose! Now I need to either get a better wrench or see if I can slightly bend the AC line out a little to get the box end on the smaller bolt and then I hope I'm good.

Progress is nice!

 

now wondering if I replace the radiator since I have things apart...