03 ls not making heat ??

[johncvt]

I have an 03 ls six and it won't make heat.After changing thermostat and flushing still no help.The guys that flushed it said it's the water pump.I replaced it and still freezing cold but no overheating or coolant loss.I am now thinking it could be the dccv or mixing valve.Is there any way to test these parts before replacing.I have also bled the cooling system following the factory manual procedure.I am grateful for any help.

 

[RigsLS]

yes I know, it's 1st GEN info but it will be close to what you need.

GEN I - Understanding Climate Control System - No Heat Information



Check the #1 fuse under hood. It's a 10A fuse, listed as A/C Clutch.
~ when the DCCV begins to short out, it will blow the fuse and thus no heat.


else ~

Perform the Front Panel DATC Module Self-Test.

You can also pull the connector from the DCCV and see if it begins to give heat. this would then confirm a faulty DATC.

Check heater hoses going in at firewall, they should be real hot, lukewarm won't do.



disclaimer: of course I stand to be corrected.


GL w/ Repair

 

[johncvt]

Awesome info lots of things I would not know to check.Thank you for taking the time to answer my question.I cannot afford to pay mechanics to throw expensive parts at this problem so being able to diagnose it myself is huge.

 

[RigsLS]

Here is the online manual for your GEN II - http://deneau.info/ls/




SECTION 412-00: Climate Control System - http://deneau.info/ls/s6x~us~en~file=s6xc0003.htm~gen~ref.htm#PS2-H

"PINPOINT TEST H: INSUFFICIENT, ERRATIC OR NO HEAT"

try following that ...

 

[johncvt]

Again I Can't thank you enough.