03 Hvac & 4x4 questions

[OilfieldTacoma]

I just got my 03 Tacoma on Monday and i have a couple of questions. I did a search and i couldn't find any answers so here goes.

1. Up until today the hvac controls have worked fine however, i switched it from vent to floor today and it will not switch back to vent only. It will blow out the far side vents but also blows hard on the floor. No center vents at all. It will switch to defrost fine but not dash vents....is this a common problem or is there an easy fix?

2. I was driving at around 65 mph today and the truck made a severe grinding noise followed by a loud "clunk". It seemed like it was trying to slip into 4hi while i was going down the road (has a floor shift). Is there any adjustment i can make to the linkage or perhaps i'm looking at the wrong area. I'm almost 100% sure it wasnt a transmission related noise

All i've owned are Chevys, so bear with me until i figure out the quirks of the Toyotas.


Basics:
2003 Tacoma Ex-Cab
3.4 V6 5spd
floor shift 4x4
90k miles

Apologies for the long winded thread and thanks in advance.

[OilfieldTacoma]

Ok, update on the 4x4 situation. Its done it three more times since i posted (allready put 1,800 miles on) It will make the grinding noise, followed by a loud clunk, then the 4x4 indicator light on the dash comes on. However......the transfer case shifter does not move at all when this is happening. It doesnt even drive like its in 4x4, but i suspect that the front diff is locking in and the transfer case isnt. Any ideas out there? Any at all?

[The Phoenix]

I'm stumped on both counts. Never heard of either problem

[EnolaGaia]

In the 2001 - 2004 Tacomas the HVAC controls are electrical, not mechanical. If I'm not mistaken there are one or more little solenoids that open and close the duct 'doors' depending on how the dash controls are set.

So my first guesses would be along the lines of:

- bad / broken / shorted connections between controls and control unit or control unit and actuator(s)
- bad circuit board in the control unit (behind the controls)
- bad solenoid / actuator / whatever

I suppose that if the duct feeding the center dash vents had come loose that might also explain it, but it seems to me you should be hearing an odd noise behind the upper dash if that were to happen ...

[EnolaGaia]

Is this Taco equipped with the TRD Off Road Package (including the electric locking differential)?

If I recall correctly it's around that speed (circa 60 - 65 mph) when the e-locker control unit should forcibly disengage the locker if it's engaged.

This should be associated with noise from the rear ...

[OilfieldTacoma]

Originally Posted by EnolaGaia

Is this Taco equipped with the TRD Off Road Package (including the electric locking differential)?

If I recall correctly it's around that speed (circa 60 - 65 mph) when the e-locker control unit should forcibly disengage the locker if it's engaged.

This should be associated with noise from the rear ...

It does have a rear diff lock, however lately its been happening at much lower speeds (10-25mpf) over very rough roads and the noise seems to be coming from the transfer case. After it makes the noise, the 4x4 indicator light on the dash comes on. Thanks for the ideas though, it gives me somewhere to look. I'm going to take it by Lewis Toyota in Dodge City on monday and let them ponder it for awhile. I'll let you know what they come up with. Thanks again.


Oh and the HVAC problem seems to have fixed itself for the time being.