92 s10 blazer - rat(s) ate vacuum line

[LarryGLack]

6 cyl. vortac engine, air, 4WD utility model. The HVAC controls quit working and I just drove it - then after a few months the heater core started leaking. I had to fix that. While I was under the dash getting ready to put the new core in, I spotted a T in a vacuum line that went to an actuator on the passenger kick panel, the line to the actuator was intact. But the T went about 6 inches then thru a rubber plug (round with a cone shape on one side) hanging in space and about an inch on the side that was cone shaped the end had been chewed off. Perhaps that is why the HVAC control quit? No other line can I find that it connected to. I have not been able to locate a vacuum diagram on the 'net. Or even find a hole somewhere within range that it might have passed thru originally. Much less the other end of the line, I guess the rats took it with 'em? Does anyone know where this line connects? or have a diagram??

[MT-2500]

Originally Posted by LarryGLack

6 cyl. vortac engine, air, 4WD utility model. The HVAC controls quit working and I just drove it - then after a few months the heater core started leaking. I had to fix that. While I was under the dash getting ready to put the new core in, I spotted a T in a vacuum line that went to an actuator on the passenger kick panel, the line to the actuator was intact. But the T went about 6 inches then thru a rubber plug (round with a cone shape on one side) hanging in space and about an inch on the side that was cone shaped the end had been chewed off. Perhaps that is why the HVAC control quit? No other line can I find that it connected to. I have not been able to locate a vacuum diagram on the 'net. Or even find a hole somewhere within range that it might have passed thru originally. Much less the other end of the line, I guess the rats took it with 'em? Does anyone know where this line connects? or have a diagram??

Where is the rubber plug located?

[LarryGLack]

Thanks for the response! I noticed it when I was putting the heater core in place, with my head under the dash looking at the top of the heater core case on the firewall when I spotted the chewed end of the line. There is an actuator on the passenger side kick panel. This actuator is in the way when replacing the heater core. There is a vacuum line that connects to this actuator from the HVAC controls up in the center of the dash, there is a T in this line a few inches from the actuator. There is about 6 inches of smaller vacuum line coming off the T - then the rubber plug with about an inch of the chewed end. It looks like the rubber plug would have went thru the firewall or sheetmetal, (I guess it could have been thru plastic) There are no holes in the heater core cover I removed. I have not been able to find the other end of the vacuum line. There does not seem to be any other vacuum operated devices on the passenger side in the area where the chewed line is hanging...

[LarryGLack]

the actuator operates the passenger kick panel vent door.

[MT-2500]

Originally Posted by LarryGLack

the actuator operates the passenger kick panel vent door.

TRY a ALL data online DIY sub. for the vacumn routing diagram.

[LarryGLack]

Ha, I completely forgot about those guys! I used to use them quit a bit, I guess I haven't needed anything for quite a few years. I notice I don't seem to have an account there any more! I will re-up and start over! Thanks for the tip!

[MT-2500]

Originally Posted by LarryGLack

Ha, I completely forgot about those guys! I used to use them quit a bit, I guess I haven't needed anything for quite a few years. I notice I don't seem to have an account there any more! I will re-up and start over! Thanks for the tip!

You are welcome I have Mitchell on demand but it is not much help.
Good luck and let us know how it goes.

[LarryGLack]

Well, I finally got around to the mystery vacuum line... There is a hole in the firewall up real high that comes out under the grill where the windshield wipers are. Right about in the center of the glove box area. That is where the rubber plug went, I guess the rats pushed out the plug? There is a vacuum actuator outside under the wiper linkage that opens an air door. I put a splice in the line as the connectors seem to be one piece with the vacuum line. Didn't fix the problem of all the air exiting via the defroster though. I hear a faint hissing near the dashboard control when the key is shut off. So I ordered a vacuum control switch and will get that put in next. The AllDataDIY fixed me up in about 5 minutes!

[MT-2500]

Originally Posted by LarryGLack

Well, I finally got around to the mystery vacuum line... There is a hole in the firewall up real high that comes out under the grill where the windshield wipers are. Right about in the center of the glove box area. That is where the rubber plug went, I guess the rats pushed out the plug? There is a vacuum actuator outside under the wiper linkage that opens an air door. I put a splice in the line as the connectors seem to be one piece with the vacuum line. Didn't fix the problem of all the air exiting via the defroster though. I hear a faint hissing near the dashboard control when the key is shut off. So I ordered a vacuum control switch and will get that put in next. The AllDataDIY fixed me up in about 5 minutes!

10-4 on the All Data