2017 Climate Control/AC IG1 No2 Fuse/MG CLT Relay

Seems like you should be able to drop it off at the Dealer and they give you a loaner vehicle until they fix the problem, no use driving around with nonfunctional climate controls.

 

Not according to my dealer. Make an appointment, bring it in for diagnosis. If parts are needed, they'll send me home with the truck and have me come back when they're in. Reasoning is that it's running, can be driven, and not a safety issue. They also close at 6pm, so whoever said that all dealers have evening service hours, that's apparently not true.

 

The best thing to do would be to use techstream to pull up whatever codes are stored since you can’t use the display to get them. That would point you where to go.

But since you don’t have access to Techstream, if you’d like to take a look at it yourself...

Take a look at the 16 pin connector on the back of the display (black in color) The a/c control assembly gets power from a 7.5 amp fuse over by the driver side junction box. It’s the light green wire coming out of the back of the 16 pin connector on the back of the control assembly. You can test it there for 12V with ignition switch ON.

On that same 16 pin connector there’s a white and black wire. You can check that one for ground.

If those two check out, I would leave that 16-pin black connector at the control unit disconnected and go over to the amplifier and disconnect the 32 pin white connector at the a/c amplifier and check the sky blue wire for resistance. (Less than 10k ohm. Should be none at all really)

Im leaning more towards the A/C control panel being dead but I’d still go over all the basics and obviously use techstream to confirm.

Again, techstream will probably show codes and make it much easier to figure out where to start.

 

My 17 sport has none of that. I thought that stuff started coming out with the '18. My '17 sport also does not come with seat heaters. I am having a hard time understanding how we can have the same year and trim level with such different features. Here is what the panel of my '17 sport looks like. Thank @MESO for the glare.....;-)

 

Here's my original window sticker if that helps.

 

I see the difference, yours has the $3065 "Premium and Technology Package" under optional equipment. My bumpers are of the same color as my vehicle, I have none of the stuff in the package. I never doubted what your truck was, just didn't understand what the difference was. It is now apparent you have a package that was not available to me with mine. Now I know! Knowledge is power!

 

I didn't take it as you doubting at all, just thought that'd help narrow down the difference. As for the package, the seat heaters and the moonroof are really the only things I benefit from. I never use the parking sonar, blind spot monitor, or cross traffic alert. They annoy me.

 

That package was available to you, it has been since 2016.

 

Was not available at my dealer at the time I bought my truck. I apologize for not clarifying that.

 

Got to the dealer late yesterday afternoon. Truck wasn't back there for maybe 15-20 mins before the tech came out, scratching his head. Asked me if the truck had ever been in a crash, front end collision, I said "Nope, never." He asked what happened when it shut off and I explained it to him. He said he's pretty confident that the actual climate control unit itself is dead, but he talked about how strange it was that it just up and failed. He thinks it's probably the computer inside of the module because running diagnostics, it isn't even responsive. It's got good power and ground, everything is plugged in, but it's like the unit just isn't even there.

He also asked me about my blind spot sensors. I told him that I don't use them, or any of the other stuff. Blind spot sensors, parking sensors, I keep all that stuff turned off, it's annoying and doesn't help me. He said it was funny, but it made sense. They are fried, there is a TSB on them, and they're going to replace them, but he didn't understand why I didn't mention it, so that made sense that I never use them.

Parts in sometime between today and Saturday. At least there's a bit of a break in the temps. Still humid, but it's a bit cooler, so I'll deal with it.

 

I wasnt aware of a tsb for the bsm to replace them. I know there is a tsb for replacing the wiring harness for the bsm.

 

And that may very well be it...? He just mentioned something with/about them being fried and getting it fixed. I just wasn't concerned about them, don't really care. Well...I guess unless I want to consider resale.

 

Got a call from the dealer on Thursday, 8/15/19, climate control unit arrived. Got an appointment for the next day (Friday, 8/16) late afternoon, they say it's going to be quick. Headed in, sat in the waiting room for maybe 20mins. Service writer comes out with some unfortunate news. He says that the new climate control unit seemed fine, but now that it's installed, it's blowing a fuse. He says we're going to have to reschedule another appointment because it's too late to start going through a full diagnosis right now. He also mentions all of my accessories. I told him that none of my accessories are tied into the climate control, they all run off the accessory power outlet circuits. I also told him I know they don't affect anything else because when I did those installs I pulled those fuses in advance and drove around to see what would happen and make sure nothing else went out if those fuses popped (if you are interested you can refer back to my threats on those installs). He wants to go talk to the tech. Tech comes out, and he is very apologetic. Talks about how he thinks it's crazy that no fuse blew but that Climate Control unit fried, and now with the new one, the fuse just keeps popping. We talked about my accessories and I told him where they were routed, he said he was sure they probably weren't interfering then. He says he's sure he can figure it out, but it's too late in the day, and he needs some time to diagnose. Apologizes up and down, he was sure that when he swapped these out it was going to cure the problem. He is scratching his head...no fuses popped before, but the control unit was fried. Now the control unit is fine, but the fuse is popping. So I had to make an appointment to drop it off for next Wednesday. No issues with the guys at the dealer...they were polite, professional, and they are trying.

On my way home I just keep turning this over in my head. When I got home, I couldn't keep my hands off it. So, here we go.

Turned the truck off, opened up some panels, disconnected all of my accessories (blue light for the FD, dash cam, radar detector). Replaced the fuse, started the truck, and the fuse popped. Ok. Not my accessories. I was 100% confident it wasn't, but just had to check.

Leaving my accessories disconnected, I also disconnected the climate control computer that he had just replaced, AND I went over to the passenger side and unplugged the HVAC fan motor. I turned the truck ON, but I didn't start it. Fuse is stable. Waited for a few minutes...it never popped. Plugged in the climate control unit...waited...didn't pop. Plugged in the HVAC fan...waited a few minutes...didn't pop. Plugged in all my accessories....waited...didn't pop. Hmm. Started the truck...POP, there goes the fuse.

Well now we've got something. Whatever this is, only happens when I start the truck. So I went under, pulled the fuse, then looked it up on the chart: IG1No.2. What is this? I whip out my phone, Google the trusty TacomaWorld website and the fuse name, I type that in...wow! Now we're onto something. I find some things related to others having that problem, and I read up that others have had this issue with the Gen2, and it is related to the MG CLT relay. K, let's try it. Open the hood, pull that guy out, put a new fuse in under the dash, start the truck...all is well. Wait a few minutes. I've got everything plugged in, fan is blowing, all is normal. Not cold obviously because the relay is pulled, but I have just narrowed this issue to that relay.

I put everything back together nice and neat. Head down the street and get a new relay, stick it in...fuse pops.

So now I am at a crossroads. I can keep going and further look at this, as it seems it is pointing to some magnetic clutch or A/C amplifier issues that others have had, but at the same time, I'm still under warranty. My next appointment isn't until 4 days from now. At a minimum I've got the climate control and the fan up and running but still no AC, and I've saved the tech a little bit of digging.

Here links to the other threads I referenced that helped guide me. They are older Gen's, but seems that the issues remain. Thank you TacomaWorld!

https://www.tacomaworld.com/threads/fuse-ig1-no-2-blowing-when-fan-is-turned-on.420339/

https://www.tacomaworld.com/threads...ier-ire-is-located-on-the-2014-tacoma.465350/

 

Look at VIOLET (#9) wire from fuse box towards A/C compressor, see if it's chewed, melted, rubbing, etc.

 

Hope you are able to figure out what is going on.

 

Found it but can’t see anything unusual.

 

It terminates in the rear of the Compressor. But at least it's nothing (so far) obvious.

 

Edited to show the Fuse and compressor juice wire and connector.

 

@caribe makaira is on the right path. I’d check that purple wire first.

BTW the light green wires go to HTR Relay and both Fan relays.

 

Also interesting that if I put the replay back in but make sure the AC is OFF, it won’t blow the fuse. When I turn the AC ON, the fuse will blow.