AC Inoperable, collective wisdom of mud help (1 Viewer)

[2001LC]

Paul, I meant the sliced open the main box in the engine bay to have a look at the relay on the underside, the 4 relays in there attached to the main board.
They cut it open and took the cover off, I assume to see the mag clutch relay. Someone suspected that before. There's an AC sig lock wire, it's blue that directly controls that, A47 pin 21 lock.

They probably also assumed replacing the screen board, and the ac amp would fix it. Which makes some sense. Without going down the fuse box-s rabbit hole.

I understand.

So many diagnosed this AC system, and slicing open main engine fuse box is going deep. They left one securing screw out and the head of the other damage in main engine fuse box. Also some metal shavings in fuse box from striping the screws head. Could be they even replace evap. More than one replace the NAV unit and AC controller/AMP. They left low pressure cap off, bugger up the OAT sensor, etc., etc. Not one could get working. I'll bet around $5k was spend on this and then rig sold because of it. Then current buyer likely is in for $2K or more. WHY could no one get working? They did not consider bad windshield install. WATER LEAKS Something those who follow the 100 tech section of mud, know too well!

I buy rigs all the time with issues, I love those deals. Have two now sitting in my driveway. One is Graybeard in my signture, the other is GrayGal (not yet posted) I'll be writing up some day, very interesting story. These were both sold due to improper diagnoses.

In the 200 section there's a story of bad windshield install, that ended in rig being totaled. After countless hour try to diagnoses and fix, they (Toyota) gave up. Land Cruiser can really handle water well. Provided it does not get into side panels of interior or in the dash, those electronics are sensitive.

I think this one a good for the books. As it is first time I've seen RH J/B take out AC.

 

[Njck22]

Goes to show how important checking the toyota service history is! A story I'm sure your familiar with. So to clarify, fiddling/cleaning with the junction box solved the issue?

 

[2001LC]

I believe so! RH Junction Block needed Reconditioning "Restoring". Knocking out what mild oxidation, improving continuity.

Water entry, produced oxidation. That this light corrosion inhabited the continuity. Knocking out so many systems at same time, must be connected, or so I thought!!!

I focused more on LH J/B Block before finding stuck fuses in RH junction box. Once I found evidence of oxidation. Focused Knowing windshield was restored by owner from bad install. Meaning rivet holes were left open, due to improper installation. "Water entry point".

 

[2001LC]

Looks like RH Junction Block (fuse box) will need replacing. Darn if AC and OAT temp read out did not work next day. Pulled RH foot well cover out and tap on J/B and jiggled wires. Then OAT temp read out came on and AC fired up. But is being buggy and works than doesn't. I notice OAT temp read out is slow to respond when IG key turned on, when it does work.

So 99% sure this is the problem, but will need to replaces the Junction Block to know for sure. No doubt in my mind, I've found the area of short, that is keeping all these systems from working.

But a 1% chances it's one of the wire housing blocks connected to J/B.

What say you guys. Does any of the attached wire housing blocks have all failures in common?

 

[2001LC]

Two most suspect wire housing blocks are, the one with dialectic grease pictured earlier and the black one with bolt holding it in.

The bolt tighten only so much than releases. The release may be designed in so one does not over tighten. Or could be one of the many "cooks" strip it. I've not compare to other 100 series as of yet. But it has a little window the show it seated all the way in.

 

[Bull Moose 100]

The bolt slips on purpose so you can't strip it.

I got this far and cleaned all these plugs that are removed in the picture plus the big black one with retaining bolt and I cleaned up all the fuses, but no luck!

Should I have gone further with the cleaning?

I couldn't figure out how to pop the yellow one off and the fan housing was in the way of the larger white plug. The plug with the two big wires is for the blower. I bet one of those wires is ground and you could run a wire from there to the chassis if you pulled the junction box and couldn't reinstall with the upper bolt that is used as a grounding point.

My AC still does not work. I can activate the compressor relay via tech stream and get cold air coming out of the vents.

Is replacing the AC amp the next step for me?

 

[2001LC]

In the case this (OP) thread dealt with. We had more than the compressor not functioning. We found a common thread for all at ground signal at this junction box. That does not mean your junction or ground(s) bad also.

So I can not answer your question. I spent a great deal of time diagnosing the whole A/C system. (10 hours). To make sure all before me, did their job correctly. In the end it was due to water entry and a ground fault at this JB RH.

But I, nor the owner ever replaced the JB. He just keeps tapping on it or rather his wife kicks, to get AC on, OAT displayed working and servor doors working functioning.

Different years have different setups for junction box LH & RH. They have their own challenges. Some you really need to pull some of HVAC (AFAIK) to remove.

 

[hb1980]

In the case this (OP) thread dealt with. We had more than the compressor not functioning. We found a common thread for all at ground signal at this junction box. That does not mean your junction or ground(s) bad also.

So I can not answer your question. I spent a great deal of time diagnosing the whole A/C system. (10 hours). To make sure all before me, did their job correctly. In the end it was due to water entry and a ground fault at this JB RH.

But I, nor the owner ever replaced the JB. He just keeps tapping on it or rather his wife kicks, to get AC on, OAT displayed working and servor doors working functioning.

Different years have different setups for junction box LH & RH. They have their own challenges. Some you really need to pull some of HVAC (AFAIK) to remove.

@2001LC, bumping on an old thread. I am having the exact same issue as your case, bad windshield install history + sunroof drains blocked. Etc. Somehow this issue had happened after I thought the issues were fixed when the car was taken for a pressure wash. Though everything seems dry. Just want to know if the main culprit was the RH JB or LH JB? And what exactly did you do to them? Replaced? Cleaned or any possible repairs?
My OAT reads -- checked voltage at connector and is 3.xx volts. Resistance on OAT sensor is 17xx ohms. Basically followed all troubleshooting and everything checks out and leads to JBs.
Also is there an easier way to remove the JB behind the blower motor? Does it all have to come out to get to it?
Thanks,

 

[2001LC]

@2001LC, bumping on an old thread. I am having the exact same issue as your case, bad windshield install history + sunroof drains blocked. Etc. Somehow this issue had happened after I thought the issues were fixed when the car was taken for a pressure wash. Though everything seems dry. Just want to know if the main culprit was the RH JB or LH JB? And what exactly did you do to them? Replaced? Cleaned or any possible repairs?
My OAT reads -- checked voltage at connector and is 3.xx volts. Resistance on OAT sensor is 17xx ohms. Basically followed all troubleshooting and everything checks out and leads to JBs.
Also is there an easier way to remove the JB behind the blower motor? Does it all have to come out to get to it?
Thanks,

By "exact same issue" you mean AC, HVAC door inop & no OAT read-out. It was at RH JB. You must check your year and model by VIN# as many combination around the world on this JB.

I felt it was the ground point of all those system not working. Which IIRC, ground was top side of RH JB. I saw no way to JB get out w/o removing that side of HVAC. Issue was the nut at top of RH JB. That nut is a ground point, so must be installed. I could get it off. But could not see way to get back on with HVAC in place, nor did I have JB with at time to try. I suppose one could build a tool to hold and place nut back on. But still the question of "will JB clear HVAC to pull out".

I also noted that a main wire block on side to rear of JB was loose, which I was unsure if that could be issue or part of.

The Mechanic I did the diagnostic for. Last I heard had not replaced the RH JB. He or his wife just kicks the RH foot well molding covering RH JB, and it fires up all systems every time.

 

[hb1980]

By "exact same issue" you mean AC, HVAC door inop & no OAT read-out. It was at RH JB. You must check your year and model by VIN# as many combination around the world on this JB.

I felt it was the ground point of all those system not working. Which IIRC, ground was top side of RH JB. I saw no way to JB get out w/o removing that side of HVAC. Issue was the nut at top of RH JB. That nut is a ground point, so must be installed. I could get it off. But could not see way to get back on with HVAC in place, nor did I have JB with at time to try. I suppose one could build a tool to hold and place nut back on. But still the question of "will JB clear HVAC to pull out".

I also noted that a main wire block on side to rear of JB was loose, which I was unsure if that could be issue or part of.

The Mechanic I did the diagnostic for. Last I heard had not replaced the RH JB. He or his wife just kicks the RH foot well molding covering RH JB, and it fires up all systems every time.

@2001LC,
Thanks for the feedback. So I'll update you on the OAT readout.. just like you mentioned, I went mad and wiggled and smacked both LH and RH JBs and the OAT read is perfect now, just miraculously. But I have a bigger issue now which entails taking the whole dash apart.. the dreaded airmix servo, that is now stuck in hot because initially when the OAT issue happened, it read out -25C which slammed the airmix in hot. Now it's stuck. It had the clicking symptoms for a while now, seems it has now finally given up.

 

[2001LC]

Also note I pulled each fuse, finding one with lots of oxidation. And those just around it, with slightly oxidation. I cleaned those fuses and the large wire block going into back side. I also sprayed electric contact clean (plastic safe) into each port as fuse or block out, followed by high pressure air. I then only "tap" on JB. I did not go "mad" on it.

I've not remove that LH JB box. Let me know how it goes. Take lots of pictures!