Last post on Nov 17, 2013 at 7:32 PM
You are in the Chevrolet Suburban & Tahoe
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Chevrolet Tahoe, Chevrolet Tahoe Limited/Z71, SUV
#551 of 762 1996 Tahoe Starting and Running Problems (Crankshaft Position Sensor)
Aug 27, 2009 (2:28 pm)
My 1996 Tahoe was having terrible problems starting and running correctly. The initial diagnosis was the crankshaft position switch was malfunctioning. After almost $2000 dollars of replacing the sensor, engine tune-up, fuel filter and fuel pump I was still having the same problems, but not all the time. I had a local mechanic due the work and he said take it to Chevy and have them diagnose the problem, which they determined was still the crankshaft position switch was malfunctioning. Since my mechanic had done the original work I took the Tahoe back to him with the Chevy diagnosis problem. He crawled under the truck with it running and saw the sensor moving around while it was running. He took the sensor out and discovered that one of the mounting bolts screws into a brass fitting inside the plastic timing chain cover. The brass fitting was loose and just needed a screw driver inserted into it to spread it to increase the tension on the plastic cover. My mechanic put it back together and it resolved all my problems, meaning most of the $2000 dollars I had spent trying to fix a problem that ended up being caused by maybe a 25 cent brass fitting in a plastic cover. Live and Learn. By the way my 1996 Tahoe has almost 154000 miles on it with the original engine and transmission.
#552 of 762 01 Tahoe LX, AC Switch
Aug 30, 2009 (12:27 pm)
How much trouble is it to change out the AC fan blower switch on the dash panel on the Tahoe. Mine just lost the three lower fan speeds. Can it be done without taking the dash apart? Thanks Doc.
#553 of 762 Re: 01 Tahoe LX, AC Switch [doc15]
Aug 30, 2009 (1:02 pm)
check the blower resistor bank, in the air plenum, by the squirrel cage.
#554 of 762 Re: knocking noise when heat is on [tahoess2004]
Aug 31, 2009 (6:21 am)
Still have the truck, and the noise. My husband said something about some door or flap or something. I don't know if he knows for sure. It sure seems related to the a/c system. If he moves the temperature lever a little off cold or hot it seems to not do it as much. It does it with heat or a/c I think. I'm not sure exactly what he was told, and I don't think it was ever officially checked out, but no real prblems with anything at this point. Did you get yours diagnosed?
#555 of 762 Re: knocking noise when heat is on [whitall]
Aug 31, 2009 (7:00 am)
The knocking noise that I experienced seemed to go away when I started using the A/C only. It occurred most often when the heater was running. I haven't got a complete diagnosis of the problem yet.
#556 of 762 Re: 01 Tahoe LX, AC Switch [doc15]
Aug 31, 2009 (11:42 am)
Check the fuses in the fuse box under the hood on the right side and make sure they are still working. If you still need to pull the dash apart to replace the switch, it does pry loose relatively easy with a flat screw driver, just be careful. All the dash switches are in unplugable panels. Where does it come apart? Right around the front edge of the dash cover is a seam. Try you hands at first pulling on it and if it pops loose then you know you are on the right track. Just take your time and be careful. Make sure you can get the replacement switch first from an auto parts place.
#557 of 762 Re: 01 Tahoe LX, AC Switch [jcb4green]
Aug 31, 2009 (2:11 pm)
If the fuse is blown would the fan blower work at all? I have some power to the switch because I have three of the six speeds. The top three fan speeds seem to work ok, just the three lower speeds are what is not working. Doc.
#558 of 762 Re: 01 Tahoe LX, AC Switch [doc15]
Aug 31, 2009 (2:35 pm)
As I said before you need to check the resistor bank (Blower Control Module) that is in the air plenum, at the output of the squirrel cage exhaust.
The blower motor is a dc motor, and you adjust speed of a dc motor by putting a resistance in series with the motor to drop voltage. That gets hot when using, which is why it's put in the duct work to keep cooled.
This is pretty common across most all vehicles, which have some sort of resistor bank or control module, This is what goes bad 99% of the time, not the switch.
#559 of 762 Re: 01 Tahoe LX, AC Switch [kiawah]
Sep 03, 2009 (4:12 pm)
kiawah speaks facts. I personally had the same problem with a Pontiac Grand AM. I lost lowest 3 speeds.
Resistors are mounted in the side of the duct work at the blower to cool them down and the resistors for the lowest fan speed always burn first as they get least amount cooling with lowest fan speeds, of course, and because the voltage drop, i.e. resistor heating is the biggest on them.
#560 of 762 Re: 01 Tahoe LX, AC Switch [arrie]
Sep 03, 2009 (5:22 pm)
Thanks for the info guys, I will be checking that out tomorrow.