Hi I have a 99 TL and My a/c is not working, so far this is what I've done, replaced blower motor and wiring harness, replaced relay, the fuse is good, & i don't think its the resistor because of what its doing.
When i turn on the ac it lights up & sounds and acts as if it going to come on the first 2 seconds then NOTHING. Any suggestions, could it be the compressor ?? I would think even if the compressor is bad it would just blow hot air... The system has been charged also.

Thanks in advance

 

get a leak test. you may not having any coolant in the lines

 

When you say that your AC isn't working, do you mean it's not blowing cold or the fan isn't working at all?

Is fan working now that you replaced the blower motor?

At the AC Compressor take a voltage reading with it unplugged. One terminal should be 12volts, the other should be ground. This says that your AC compressor is getting power but still not turning on, which means your compressor clutch isn't energizing.

When the AC was charged did you use an AC machine most shops have? They are supposed to do a recover which removes all the refrigerant. Then a 15 minute vacuum test which shows if your lines have any major leaks. Any small leak you would be able to visually see.

It's a PITA to diagnose an AC system by just throwing parts at it. So try these guidelines first! Good luck.

 

Hey guys and thanks, It was the resistor ... the theory i had turned out to be true, when my old harness burned out blowing my motor it also sent a negative charge to the resistor which also acts as a ground. So anyway its fixed, but Its not as cold as it was, so I guess I'll take it to a good shop maybe even dealer and get it checked out like tech05 said so all the proper test can be done ... if anyone in the orlando area with equipment and know how is available let me know ... I'm trying to save as much money as possible but get the job done right.
Thanks for all the Help.

 

Glad you traced down that issue. Resistor problems are common with modern day HVAC issues. They can even give the most seasoned tech the run around with the different symptoms they cause.

 

I am having the EXACT same issue. I have a 99 TL.

My AC was working just fine and then one day it just didn't turn on. I had someone inspect it and they said it might be the switch on the dashboard. This seemed odd...

Anyway... I am trying to figure out where the resistor is so I can have a look.... I suspect I may have the same issue as mrmajor

 

Alright so I have changed the resistor... it works and the air blows... BUT it only blows hot. I have tried the AC at the coldest and it still blows hot.

Now im thinking an additional problem is the motor itself.

I think im about 1/2 way there fixing the problem...


mrmajor your inbox it full. I was trying to reply to your message.

 

Anyone? I'm still trying to figure this out...

 

If the blower motor is now working check to see if the compressor is cutting on. If not cutting on check for power if no power check to make sure the ac system has enough freon to make the pressure switch cut the compressor on, or it could be fuses or a relay. if you are getting power make sure fans are operating properly when the compressor is on. if they are working and the ac is cutting on you most likely are low on freon.

 

All the fuses look good. The relay looks good as well. I also took the filters off and cleaned them up. (new ones are being shipped).

Since the resistor was blown... what would be the likely cause of that? maybe tracing it back to this might lead me to the underlying problem.