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Did you ever find it? I am seeking the same for my RX330 2006. I got advice to look for the relay marked MG/CLT in the relay box under the brake fluid reservoir but there is no such relay in that box. The only possibilities are EFI Main or A/F, neither of which seem right. How did you finally resolve your problem? thanks
You are correct that EFI is fuel injection. EFI stands for Electronic Fuel Injection.
The a/c relay, MG/CLT, is not a mechanical relay. It is a solid state relay, essentially a fancy transistor. It is not located in with the relays below the brake fluid reservoir. It is in JB2 (Junction Block 2) located below the fuses that are in front of the brake fluid reservoir.
I have never opened up JB2, so I can't give you any more details.
The journey continues. My mechanic found the error code was for the relay however, he got one from the Lexus dealer ($175 his cost) replaced it, and it did not fix the problem. He believes it may be an electrical problem so I am going to an electrical specialist. Below is a picture of the relay. It is huge (stapler shown for scale). The entire "black box" shown is the relay. It's located in front of the JB2 on the right of the engine compartment (facing the car, the one DennisMik describes). It actually plugs into the front of the JB2 and looks like part of the block. It sits vertically vs. the picture below that shows it horizontally. Imagine turning this by 90 degrees and standing it on the edge. The part of the relay that is on the top in the photo is the part that plugs into the front of block. (I'll take a picture of it in situ and post that later).
Last edited by MickeyMac; 08-31-19 at 10:38 AM.
Reason: More detail
Good grief!!! That is the whole junction block. Evidently Toyota doesn't sell the relay by itself. Not unusual. I needed a $3 microswitch for my IS convertible and I had to buy the complete mechanism it is mounted on with electric motors for $1400!
If you were to open up that junction block, you would find the relay inside it.
Thank you for showing what junction box looks like. Do you have the photo of the HVAC compressor relay? Want to verify and avoid buying the wrong item.
By the way, it seems hard to take off the junction box. Is there anything we need to pay attention to as doing it ? Thanks.
The work was done by my mechanic so I don't have any tips about how to do it. I know the stated amount of time to remove and reinstall was expected to be 1.5 hours of labor. They did it more quickly than that as it turned out not to be the problem so they just quickly put the old one back rather than do all the other activities around ensuring the full job was done.BTW, my mechanic hasn't charged me for anything. I love those guys!
Sorry, don't have photos of other components.
Last edited by MickeyMac; 09-03-19 at 02:17 PM.
Reason: typo
I took the junction block apart and still can’t find the relay.
I took the entire junction block out, and still can’t find the relay. Does the entire junction block have to be replaced?
Originally Posted by MickeyMac
The work was done by my mechanic so I don't have any tips about how to do it. I know the stated amount of time to remove and reinstall was expected to be 1.5 hours of labor. They did it more quickly than that as it turned out not to be the problem so they just quickly put the old one back rather than do all the other activities around ensuring the full job was done.BTW, my mechanic hasn't charged me for anything. I love those guys!
Sorry, don't have photos of other components.
I took the entire junction block out, and still can’t find the relay. Does the entire junction block have to be replaced?
Hi friend, like Dennismik says above and from what I'm looking at in the drawings and the best I can make sense of it, the relay is actually a FET transistor sourcing voltage to the AC clutch.
On the circuit board plz notice the markings "FET" and this unit has several of them for switching on and off many different things by the looks of it.
This diagnostic is doable depending on how far someone wants to go and will require some skill with a volt meter but no test lights on digital circuits should be used to avoid possible damage to the other ECU's inputs/outputs on the car this junction box is connected to. Just wanted to throw that out there...
Is your compressor clutch not engaging or is it on all the time?
My 2005 Australian Rx330 has no traditional AC relay. Pretty sure the Junction box has solid state relays for a couple of things, as speculated. They are generally much more reliable as long as the connected device does not fail. You sure it is the relay, not one of the climate control motors? The old trick for turning the temp up high for a minute and turning it back down works for me. Still, some online sellers will still try to sell you a traditional style relay... Buyer beware.
A/C Relay
07-06-19, 06:13 AM
