I didn't want to start another AB blinking thread. But I'm at a stopping point.
I reinstalled my engine after a reseal with a new compressor. All was working fine for for the last 5 years with the old compressor.
I changed the evap front and and condenser in late 2019.
After install I vacuumed and let it sit for many hours. It seemed like it was perfect.
I charged a liquid 12 ounces in the high side.
I started the engine and hit the AC button, no engagement with blinking light.
Checked a few things and then gave up for the night after checking fro HVAC codes and only showed the 21, solar sensor.
Next morning my pressures were equalized at about 60 psi with an ambient of about the same. This was with one 12 ounce can charged from day before.
I hooked up another can and got ready to try again and the clutch engaged and the AC started blowing normally again. One thing I didn't see was cycling on off pressures. But it was colder than normal for me when doing AC. ALso, I could not hear the clutch engage it is much more quiet than the older compressor. The only give away was the idle bump.
I was showing the low side in a range of 25-35 psi and the high side a tiny bit lower than 200 psi.
I charged 38 ounces in total, by weight in one single session with the engine running. Everything was normal.
Ten hours later I went for a drive. AC would only blink after 3 seconds.
Next morning, even warmer ambient, pressures equalized around 75 psi. High side was slightly higher by 5-10 psi. Ambient was about the same, around 75
Clutch would not engage.
I used techstream to check the AC sig. That works normal. That's the button press on the dash and the network knows it and shows in techstream that it was in fact pushed.
All my hvac circuit boards are a little bit over 4 years old.
The lock on the compressor ohms out fine.
I can't get battery voltage on the mag clutch wire unless I give it 12 volts at the compressor plug, or at the connection by the main ECU behind the glove box.
I know it works sometimes.
I know the AC fuse is good because all the other components of the hvac work normal. I have no codes but the solar sensor and the other hvac secondary test is normal.
I do not believe I have a continuity issue. That AC harness, which is part of the starter harness and secondary intake loom looked good and I cleaner it all out.
I know it's good.
Next day, yesterday, I couldn't get the clutch to engage at all. Techstream won't either, where it did on the first day of testing.
Following the fsm, at this point, would have you take down the center assembly and look at the big 40 pin ac amp plug, the ecu main, the main fuse box up and undone, and the 3 pin compressor connector (harness side)
I do not want to do that unless I have a new fuse box in hand. Which I ordered. BTW, partsouq doesn't carry them anymore. South Atlanta is cheapest @ $570.
I wont do that until I replace the pressure switch and re vacuum, that's on the way, as is another drier.
Today is the 4th day. Haven't had the compressor engage since the second day. When it did, it was after a dead cold start.
My thoughts are this,
push the AC button, it either engages and turns or it doesn't. If it doesn't, the lock signal automatically gets sent because of the mismatch. Then the blinking after 3 seconds.
If it engages, all is good, cold air happens until it gets hot and then something happens, either lost relay power, or a true mismatch in RPMs. (I doubt)
The AC sig line is normal.
Techstream can't send a lock signal if the clutch is not engaged. Which I can't-- right now I'm thinking I can give the clutch 12 volts and then have techstream send the lock signal without the car running. Would that work. the lock signal gives it the ground correct? I do not know if pushing the AC button with the ignition on but not started engages the clutch. It's so quiet.
I do not believe my pressure switch is bad, but I'm replacing it anyway.
of the few people I know of that have replaced the fuse box in the 100s that have that relay soldered into the main board, it has solved their issue. I want to believe that's it. But really I think it's something else.
too much oil in the system. I emptied the old compressor and hardly any oil came out. I swapped the service plate, everything's good there.
When I initially removed the two pipes from the compressor to remove the engine a fair bit of oil came out of the two lines and almost none out of the old compressor. I removed about half the oil that came with the new compressor. It's the denso, not the toyota parts counter item.
When I had added r134 in the past 2-4 years I have always done it at night, when it's about 90 degrees out. I could see the cycling of pressure with engage/ disengagement.
It did not cycle one time while I added the last two cans. The clutch stayed engaged the whole time, maybe 30 minutes or more. My high side would not climb like it has in the past to 200 psi. But this was the coldest I've ever done AC charging. It was 65-68 ambient.
this turned into a book, I know.
I'm going to go through the motions of the FSM when a new fuse box shows up. I figured why stop there? and bought a vacuum pump along with it. I'll update with that, if it solves it. And how and where to test the clutch relay wires at or close to the fuse box.
There's only a couple years of the 100s that have this MGC relay set up, it's horrible. Even the two hundreds have a replaceable relay.
sorry this got so long. This is why I didn't want to write it. Too many variables.
I reinstalled my engine after a reseal with a new compressor. All was working fine for for the last 5 years with the old compressor.
I changed the evap front and and condenser in late 2019.
After install I vacuumed and let it sit for many hours. It seemed like it was perfect.
I charged a liquid 12 ounces in the high side.
I started the engine and hit the AC button, no engagement with blinking light.
Checked a few things and then gave up for the night after checking fro HVAC codes and only showed the 21, solar sensor.
Next morning my pressures were equalized at about 60 psi with an ambient of about the same. This was with one 12 ounce can charged from day before.
I hooked up another can and got ready to try again and the clutch engaged and the AC started blowing normally again. One thing I didn't see was cycling on off pressures. But it was colder than normal for me when doing AC. ALso, I could not hear the clutch engage it is much more quiet than the older compressor. The only give away was the idle bump.
I was showing the low side in a range of 25-35 psi and the high side a tiny bit lower than 200 psi.
I charged 38 ounces in total, by weight in one single session with the engine running. Everything was normal.
Ten hours later I went for a drive. AC would only blink after 3 seconds.
Next morning, even warmer ambient, pressures equalized around 75 psi. High side was slightly higher by 5-10 psi. Ambient was about the same, around 75
Clutch would not engage.
I used techstream to check the AC sig. That works normal. That's the button press on the dash and the network knows it and shows in techstream that it was in fact pushed.
All my hvac circuit boards are a little bit over 4 years old.
The lock on the compressor ohms out fine.
I can't get battery voltage on the mag clutch wire unless I give it 12 volts at the compressor plug, or at the connection by the main ECU behind the glove box.
I know it works sometimes.
I know the AC fuse is good because all the other components of the hvac work normal. I have no codes but the solar sensor and the other hvac secondary test is normal.
I do not believe I have a continuity issue. That AC harness, which is part of the starter harness and secondary intake loom looked good and I cleaner it all out.
I know it's good.
Next day, yesterday, I couldn't get the clutch to engage at all. Techstream won't either, where it did on the first day of testing.
Following the fsm, at this point, would have you take down the center assembly and look at the big 40 pin ac amp plug, the ecu main, the main fuse box up and undone, and the 3 pin compressor connector (harness side)
I do not want to do that unless I have a new fuse box in hand. Which I ordered. BTW, partsouq doesn't carry them anymore. South Atlanta is cheapest @ $570.
I wont do that until I replace the pressure switch and re vacuum, that's on the way, as is another drier.
Today is the 4th day. Haven't had the compressor engage since the second day. When it did, it was after a dead cold start.
My thoughts are this,
push the AC button, it either engages and turns or it doesn't. If it doesn't, the lock signal automatically gets sent because of the mismatch. Then the blinking after 3 seconds.
If it engages, all is good, cold air happens until it gets hot and then something happens, either lost relay power, or a true mismatch in RPMs. (I doubt)
The AC sig line is normal.
Techstream can't send a lock signal if the clutch is not engaged. Which I can't-- right now I'm thinking I can give the clutch 12 volts and then have techstream send the lock signal without the car running. Would that work. the lock signal gives it the ground correct? I do not know if pushing the AC button with the ignition on but not started engages the clutch. It's so quiet.
I do not believe my pressure switch is bad, but I'm replacing it anyway.
of the few people I know of that have replaced the fuse box in the 100s that have that relay soldered into the main board, it has solved their issue. I want to believe that's it. But really I think it's something else.
too much oil in the system. I emptied the old compressor and hardly any oil came out. I swapped the service plate, everything's good there.
When I initially removed the two pipes from the compressor to remove the engine a fair bit of oil came out of the two lines and almost none out of the old compressor. I removed about half the oil that came with the new compressor. It's the denso, not the toyota parts counter item.
When I had added r134 in the past 2-4 years I have always done it at night, when it's about 90 degrees out. I could see the cycling of pressure with engage/ disengagement.
It did not cycle one time while I added the last two cans. The clutch stayed engaged the whole time, maybe 30 minutes or more. My high side would not climb like it has in the past to 200 psi. But this was the coldest I've ever done AC charging. It was 65-68 ambient.
this turned into a book, I know.
I'm going to go through the motions of the FSM when a new fuse box shows up. I figured why stop there? and bought a vacuum pump along with it. I'll update with that, if it solves it. And how and where to test the clutch relay wires at or close to the fuse box.
There's only a couple years of the 100s that have this MGC relay set up, it's horrible. Even the two hundreds have a replaceable relay.
sorry this got so long. This is why I didn't want to write it. Too many variables.
