What’s going on guys i’ve got here a 2000 chevy tahoe and i’m using this car to point out to you the location of the important fuses for the operation of the ac i’m also going to show you the location of the ac relay and give you some troubleshooting steps for things to look out for when your air conditioning is not working so we’re going to begin by opening up
This cover here we just pull it open like that and we can see on the back there’s some spare fuses and there should be a fuse puller there as well that could be useful for you now looking in here we’re gonna find two fuses that work to provide power to our hvac control unit so that’s the piece that uh has the buttons on there that you uh operate so the first one
Is this 25 amp fuse and power from this fuse is used mostly for the blower motor and i’m just going to go and pull it out here so this is for the blower motor to operate there’s a 10 amp fuse in here as well all the way there up in the upper left hand corner and power from that fuse is used for the actual ac button as well as the mode the mode doors so check
Those two out now we can move under the hood this is where we’ll find the ac relay and i’ll also give you some troubleshooting steps for how to test the compressor and common things to look out for that can cause your air conditioning to be disabled so we’re going to look inside the electrical center here we just open this up by pulling it up like so now there’s
A fuse puller some spare fuses up here and this is where we’ll find the ac relay so the ac relay is this relay right here and when this relay activates it sends power to the ac compressor using power that it receives from the 10 amp ac fuse right here so let’s get this pulled out here so this is a good fuse and i’m putting it next to a blown fuse for comparison
Another fuse that’s necessary for this relay to work is this 10 amp fuse here now as far as troubleshooting goes my favorite way to troubleshoot the ac relay is to have the car running with the air conditioning turned on i’ll then come here and i’ll tap on that relay sometimes relays can get stuck and by tapping on the relay you can get it to start working again
Further troubleshooting what we can do is actually remove the ac relay set it aside and swap in a different relay i would suggest swapping in the horn relay because if your horn works you know that your horn relay works so if we swap in our horn relay and then our ac starts to work well then we know our original relay is probably no good now let’s talk about the
Wiring of this relay you can see i’ve got these pins color coded so we can go over what each one does now the 10 amp fuse that’s located right here this provides power at this pin right here there’s another power coming from our ignition e fuse that comes in here now when you turn your air conditioning on when you press that little ac button what you’re really
Doing is you’re actually telling the powertrain control module that you would like to have the ac on the powertrain control module runs through a number of checks and if it decides that it’s a good idea to run the ac it will provide a ground signal here that is what activates the relay if you never receive a ground signal here from the powertrain control module
Then there’s something that’s causing it to disable the air conditioning this can be anything from a misfire your check engine light could be on maybe your refrigerant has leaked out so you need to look into that further but when everything’s working properly and the ground is provided here it will activate this relay and when this relay is activated it sends power
From this pin into this pin so this pin actually goes to the ac compressor you yourself can provide your own power here that will cause the ac compressor to engage be careful when you do this though because you can damage your air conditioning system if you have low refrigerant if you have too much refrigerant if your engine is not running properly so that’s just
A troubleshooting step only connecting those two pins will cause that ac compressor to engage so basically to summarize we’ve got our two fuses here and here we’ve got our ac relay there are the two fuses i showed you that are inside the car let’s talk a little bit about the most common culprit that will disable your ac and that is if you have a slow leak of
Refrigerant so there’s a sensor here that the car will use to determine if you have enough freon and uh once enough freon leaks out the car will disable your ac you can check the level of refrigerant in your system using these two ports so you can actually add refrigerant as well so yeah they sell kits at part stores that you can use for adding refrigerant and
As i’ve mentioned earlier if your check engine light is on you’ll want to look into that before you start going too in depth on the ac stuff now uh i’ll leave you with this i just wanted to point out to you the location of the ac compressor so it’s way down here at the very bottom and there is a connector here i’m shining my flashlight on it right there and
There’s a ground there’s also power there the power comes through from the ac relay engaging so yeah i hope that this information has been helpful for you or at the very least a good starting point in troubleshooting the ac on your tahoe please do let me know if you have any questions or any advice and thanks for watching
Transcribed from video
2000 Chevy Tahoe AC Fuses & Relay, Air Conditioning Troubleshooting By Lehew Tech