GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello, yes I might have some answers for you but we will need to work together on this one. Lets start with the water on your passenger floor. Have you touched or smelled it? coolant has a certain sweet smell and can be slightly sticky feeling. if It is water an d I think it is. Our next step is to determine is it water leaking out of the hvac from your evaporator condensation or is from an external water leak. Did you notice this water after a heavy rain or car wash situation?
Could be a situation with your drain being clogged or damaged. first step I would suggest is run it with the a/c on and inspect the drain to see if it is working.
now what about your floor vents not working. as in they wont switch or?
the drain is under the hood on the fire wall by where the two shiny a/c lines attach. it might be a little hard to see. I beleve it has a seal around it too. if that seal is damaged or missing the water my be draining back into the cab. Locate it and let it run while watching what is going on. If that seems fine you then should remove the lower kick panel and inspect all around the case and case parts for leaks.
as for your blower non working on #5, I would suspect the blower resistor is the issue, It may also be damaged from the water leaks. you could remove it to inspect it. It is located under the dash on the passenger side close to the blower motor. it has one large flat plug and two small copper/gold color bolts.
As for floor vent issue that may be simply a bad actuator or more. without a scanner you cannot check for codes. The simplest test you could do is remove the mode act and manual turn the door and see if it moves smoothly and to the vent pos. do this with the blower going to see how the air moves. then from there you can decide to replace the act or take it too a shop. if you replace the act take the battery cables off for a few mins so that when you hook them up it can hopefully reset your hvac without needing the scan tool. otherwise you might need a dealer visit,
I assumed you have auto hvac this is were that act is
let me go look to make sure you have the right picture then
ok it is the same for both
this shows you were the resistor/processer is
for the resistor You may or may not have a cover panel if you get down look under the dash on the pass side if there is a large smooth plastic cover remove that and it should look like the picture. as for the mode actuator it is accessed from the drivers foot well. depending on the build of yours you might need to remove a cover and a few brackets. If I remember correctly those mode act are pretty tight to access.