Compressor not turning on (1 Viewer)

[jsloden]

It's on the side of the transmission where the shifter connects to it. Normally when they malfunction they will through a CEL.

 

[Anvil]

Thanks

It's on the side of the transmission where the shifter connects to it. Normally when they malfunction they will through a CEL.

Thanks jsloden! I apologize if I hijacked the thread. It wasn't my intent. I rebuilt my cooling system last year and want it back!!

So I'm guessing do a continuity check from switch to amplifier connector? I have no CEL light. I welcome ideas/advice! you guys feel free to chime in. Thanks!!

 

[rdcnj]

Can someone please tell me where the switch circled below is located? I used the FSM and volt meter to check the plug going to the amplifier. All was good except this wire. It should be supply 10-14 volts. It has nothing. Thanks!


View attachment 2659345

Park/Neutral position switch , location and photos - Attached to trans - 96 FZJ80 starts in any gear - park/neutral safety switch - https://forum.ih8mud.com/threads/96-fzj80-starts-in-any-gear-park-neutral-safety-switch.262349/post-4062182

 

[rdcnj]

Thanks


Thanks jsloden! I apologize if I hijacked the thread. It wasn't my intent. I rebuilt my cooling system last year and want it back!!

So I'm guessing do a continuity check from switch to amplifier connector? I have no CEL light. I welcome ideas/advice! you guys feel free to chime in. Thanks!!

Amp draw check, continuity isn't good enough to check load. Just confirms that at least one strand of wire is connecting.

 

[Anvil]

Amp draw check, continuity isn't good enough to check load. Just confirms that at least one strand of wire is connecting.

Thank you sir! You've been a big help today. Here's one place I'm cofused (there are many!)... If I read the diagram ciorrectly, it shows the current comes out of the amplifier on #5/black wire. The FSM says there should be 10-14 volts coming in with engine running. #5 is the only wire that did not test good, it had 0 voltage with engine running. So I should test for voltage at the park/nuetral switch next? Thanks again!

 

[rdcnj]

Thank you sir! You've been a big help today. Here's one place I'm cofused (there are many!)... If I read the diagram ciorrectly, it shows the current comes out of the amplifier on #5/black wire. The FSM says there should be 10-14 volts coming in with engine running. #5 is the only wire that did not test good, it had 0 voltage with engine running. So I should test for voltage at the park/nuetral switch next? Thanks again!


View attachment 2659540

I would backprobe the #5 wire with the engine running, see what comes out. Make sure you're making a good connection to the spade in the connecter with is back probed.

Not going to be easy with the location of the connector.

If you don't have battery voltage there, I would say you may have to start there.

If you do have battery voltage there, then you need to go to connector IH1 - check there for battery voltage, then up to connector IG2 (which a fair amount of the A/C Amplifier wires seems to run through).

 

[Anvil]

I would backprobe the #5 wire with the engine running, see what comes out. Make sure you're making a good connection to the spade in the connecter with is back probed.

Not going to be easy with the location of the connector.

If you don't have battery voltage there, I would say you may have to start there.

If you do have battery voltage there, then you need to go to connector IH1 - check there for battery voltage, then up to connector IG2 (which a fair amount of the A/C Amplifier wires seems to run through).

I can't thank you enough for your help! I'll give this a try tomorrow.

 

[landcrshr]

I would backprobe the #5 wire with the engine running, see what comes out. Make sure you're making a good connection to the spade in the connecter with is back probed.

Not going to be easy with the location of the connector.

If you don't have battery voltage there, I would say you may have to start there.

If you do have battery voltage there, then you need to go to connector IH1 - check there for battery voltage, then up to connector IG2 (which a fair amount of the A/C Amplifier wires seems to run through).

I can't thank you enough for your help! I'll give this a try tomorrow.

I'm pretty sure that #5 wire only gets +12V when you're actually cranking the starter.

 

[Anvil]

I'm pretty sure that #5 wire only gets +12V when you're actually cranking the starter.

Thank you landcrshr! I'll test that today.

 

[Anvil]

I'm pretty sure that #5 wire only gets +12V when you're actually cranking the starter.

Landcrshr, you were correct! #5 wire has power for a second or two while the starter is engaged. Now I'm back where I started... I've tried two amplifiers with no success.... hmmm...

 

[jsloden]

The two quickest things to rule out are the low pressure switch and the thermistor. You can simply make a jumper with a piece of wire or a paper clip and jump the plugs. Should take 10 minutes. There's also the relay the on top of the evaporator box. If I remember correctly the voltage passes through the relay after the amplifier. So even if the amplifier tests good the compressor still will not turn on if the relay is bad.

 

[Anvil]

The two quickest things to rule out are the low pressure switch and the thermistor. You can simply make a jumper with a piece of wire or a paper clip and jump the plugs. Should take 10 minutes. There's also the relay the on top of the evaporator box. If I remember correctly the voltage passes through the relay after the amplifier. So even if the amplifier tests good the compressor still will not turn on if the relay is bad.

Thank you jsloden! I honestly can't thank you guys enough. I truly appreciate everyones time.

I'll give that a try tomorrow. I'm determined to figure this out. I failed to mention earlier, I had taken my rig to an ac shop... they were stumped and couldn't fix the problem.

Thanks again!!

 

[Anvil]

I finally found time to jump the thermistor plug... Nothing changed, so I guess the thermistor is good. Though I did buy a new one and will replace it soon, just because that's the way I am...

Does anyone have a trick to removing the round relay above the evaporator (circled in red)? I wanted to get a part number off of it. EDIT: I found the part number for the round relay online, it's 90987-03001.

Where does the #7 relay 88630-20020 (circled in blue) live? I'm still looking for it...

Thanks again guys!

 

[LandCruiserPhil]

I finally found time to jump the thermistor plug... Nothing changed, so I guess the thermistor is good. Though I did buy a new one and will replace it soon, just because that's the way I am...

Does anyone have a trick to removing the round relay above the evaporator (circled in red)? I wanted to get a part number off of it.

Where does the #7 relay 88630-20020 (circled in blue) live? I'm still looking for it...

Thanks again guys!

View attachment 2665387

maybe post #18

 

[jsloden]

If you look up on top of the evap box you might be able to see it. You may have to get a small mirror. Once you can see it though it's fairly straight forward. You just pull it straight out. I would also use a jumper on the low pressure switch as well. Just to try it. It could also be the coolant temp sensor. It's going to be one of the sensors on the side of the engine. I don't remember which one at the moment but if you google it there are multiple diagrams of it.

 

[Anvil]

Thanks jsloden and LandCruiserPhil! I truly apprciate your time!!

There is a relay behind the glovebox that gave me the same problem on a 1996

Was your bad relay the round relay, or the rectangle relay that I haven't found yet?

 

[Anvil]

I finally found time to troubleshoot again... I replaced the round relay, jumped the low pressure switch connector, jumped the thermistor connector, jumped the coolant temp sensor, and still no compressor engaging.

Am I correct to assume there are only two components remaining that could be bad? The amplifier and the rectangle relay? I installed another amplifier I bought off ebay. I guess there is a chance of both being bad. I believe the relay is a Blower Speed Control Relay... my blower works fine.

Any advise will be much appreciated. Thanks!!!

 

[jsloden]

You may have stated this in an earlier post but have you tried applying 12v to the compressor?

 

[Anvil]

Yes sir, the compressor engages when 12v is applied.

I tried ordering a new amplifier. Unfortunately, there is a national backorder on this part. Toyota doesn't know when the part will be in stock.

 

[jsloden]

With all of the switches jumped were you able to get any sort of voltage coming out of the blue/white wire on the amplifier? If you were then there's either a break in the wire somewhere or the engine coolant temp relay is bad.