99 Blazer no 4wd and no ac

Had some transmission problems and decided to have it rebuilt at a shop. Prior to having it towed in i had pulled it up on ramps (i put it in 4lo to get up on the ramps). It sat there for about 6-8 weeks, on the ramps and still in 4lo.
Had it towed in and tranny rebuilt. When i got it back had no 4wd, and later noticed that the ac no longer functioned (just blows warm air).When i start the truck the 4wd buttons all flash, then the auto flashes and it usually goes to 2wd., pressing auto, 2hi,4lo ,4hi does nothing, service 4wd light comes on. If it stays in auto, it feels like its in 4wd. Transmission shop read codes - c0367 and b2725, they don't do transfer case problems. 99 blazer, AT, 4 button on dash 4 wd switch. Prior to tranny probs 4wd and ac worked, any help greatly appreciated. thanks

Hello,

this is definetely a Vacuum Problem. Had this 2 Months ago. Check all Vac-lines, you may search the Forum for 4wd problems, i found an article (with pics) here that helped me a lot

Had some transmission problems and decided to have it rebuilt at a shop. Prior to having it towed in i had pulled it up on ramps (i put it in 4lo to get up on the ramps). It sat there for about 6-8 weeks, on the ramps and still in 4lo.
Had it towed in and tranny rebuilt. When i got it back had no 4wd, and later noticed that the ac no longer functioned (just blows warm air).When i start the truck the 4wd buttons all flash, then the auto flashes and it usually goes to 2wd., pressing auto, 2hi,4lo ,4hi does nothing, service 4wd light comes on. If it stays in auto, it feels like its in 4wd. Transmission shop read codes - c0367 and b2725, they don't do transfer case problems. 99 blazer, AT, 4 button on dash 4 wd switch. Prior to tranny probs 4wd and ac worked, any help greatly appreciated. thanks

Code C0367 is for front axle control circuit high.
Shorted actuator or wiring circuit.

The B code I can not find for you blazer.

On AC check for proper R-134-a charge and presser switches.
Also fuse.
Does the compressor kick in any?

Code C0367 is for front axle control circuit high.
Shorted actuator or wiring circuit.

The B code I can not find for you blazer.

On AC check for proper R-134-a charge and presser switches.
Also fuse.
Does the compressor kick in any?



nope, checked all related fuses(hvac,ac,illum), removed connector from compressor and checked voltages, at that connector, getting .05, found an inline diode on same line, going to replace diode tommrow ,

removed battery and checked vacuum actuator and cable, cable was corroded pretty bad, after disconnecting i tried pulling on it, didn't get much movement at all. will report back on findings, thanks again:iceslolan

nope, checked all related fuses(hvac,ac,illum), removed connector from compressor and checked voltages, at that connector, getting .05, found an inline diode on same line, going to replace diode tommrow ,

removed battery and checked vacuum actuator and cable, cable was corroded pretty bad, after disconnecting i tried pulling on it, didn't get much movement at all. will report back on findings, thanks again:iceslolan

You are welcome.
On the diode it will not keep compressor from turning on.
It is for controlling voltage spikes when compressor kicks in and out.
Start at and try jumping the two wires at low pressure switch.
But do not try applying 12 volts there if a automatic air system.
Is this automatic AC controls?

You are welcome.
On the diode it will not keep compressor from turning on.
It is for controlling voltage spikes when compressor kicks in and out.
Start at and try jumping the two wires at low pressure switch.
But do not try applying 12 volts there if a automatic air system.
Is this automatic AC controls?


removed connector at low pressure switch and put in jumper wire and started car and i think the compressor kicked on, will check again later as kids and grand kids just showed up. thanks
:smokin:

If so the low pressure switch is bad or it is low or out of R134a
May be time to get the pressure gauges and check it.

removed connector at low pressure switch and put in jumper wire and started car and i think the compressor kicked on, will check again later as kids and grand kids just showed up. thanks
:smokin:



sometimes when something fails when something else fails , we tend to think the failures are related, and ignore the obvious, thanks mt for putting me back on right track, checked pressue, needed coolant. i would have bet it was a vacuum problem and have been chasing that vacuum problem that did not exist. thanks again:smokin:

10-4 on that.
And sometimes we blame the last person that worked on it.
Bust as aways we need to check it out good first.
You are welcome and thanks for posting back how it went.
Glad you got the AC going good.
MT