2003 i35 air condition

[3.0maxima]

Recently I have purchased '03 infiniti i35 and I have noticed that there was no freon in the system, after filling it, the air compressor engages regardless of the temperature (heat/air cond 60 or 90degrees) is is always on. Is this normal for infiniti, or is ther something not working properly,, any help will be appriciated,,,
Thanks

[Nahkapohjola]

Originally Posted by 3.0maxima

Recently I have purchased '03 infiniti i35 and I have noticed that there was no freon in the system, after filling it, the air compressor engages regardless of the temperature (heat/air cond 60 or 90degrees) is is always on. Is this normal for infiniti, or is ther something not working properly,, any help will be appriciated,,,
Thanks

Check out from the maint manual how filling is done & troubleshooting tables. Then take to a shop...

See links below, I guess '02 manual is ok.

[3.0maxima]

I have done the onboard diagnostics via temp control unit (has built in diagnostic tool) checked all of the sensors, everything works fine heat/cold, accept that theair compressor is always on, i have also checked the plug on the condenser itself and there is 5v between two outer pins and voltage is not switchingto other pin with temp change, will look into it more and will update the posts..
thanks..

[Nahkapohjola]

Originally Posted by 3.0maxima

I have done the onboard diagnostics via temp control unit (has built in diagnostic tool) checked all of the sensors, everything works fine heat/cold, accept that theair compressor is always on, i have also checked the plug on the condenser itself and there is 5v between two outer pins and voltage is not switchingto other pin with temp change, will look into it more and will update the posts..
thanks..

The diags diagnose only new systems, those problems that may be planned... very seldom help.

It could simply be the compressor relay contacts jammed; find it and knock with screwdriver to loosen. Measure if it is always energized: if no voltage, Replace.

There is single +12V wire to compressor, supplied via relay contacts. This relay is supplied always from Fused +12V.
The relay coil gets Ign on Fused +12V (another fuse) and is grounded from ECU pin 21. When ECU pin goes down, relay is closed, compressor gets +12V.

If that ECU pin is always down, then its not the relay... ECU has the last word as it always disconnects compressor on full throttle.

[3.0maxima]

i forgot to mention that when the heat/air cond if off the clutch on the compressor releases.. could that still be a relay??
Thanks for your help..

[Nahkapohjola]

Originally Posted by 3.0maxima

i forgot to mention that when the heat/air cond if off the clutch on the compressor releases.. could that still be a relay??
Thanks for your help..

That kinda drops relay theory off the shelf.

Put a multimeter with extension wire to the circuit and test drive and see if disconnects on full throttle. If so, ECU is OK, and your problem comes from A/C circuit board. That board might be quite expensive: howabout just living with this: tell like microsoft that from now on this is THE feature, not problem?

Where to connect tst probe is good question: i'd think easiest accessible is the single connector in the compressor. Unplug it, insert long wire inside (first bare it ½inch) and plug it back hoping it will be inside and make connection. Then route the wire outside onto pass seat, connect multimeter and tsts drive. Use duct tape.

To tst my AT gearlock, I built extension wire to TCU cable, see http://www.cardomain.com/ride/748507/15 ...but maybe not necessary in this issue.

[3.0maxima]

Thanks alot, will try it once i get home from work,,