Dash gauges do not work, heater controls do not work

Is it only the gauges or the all the instruments and heater controls? The first place I'd look at will be the dimmer switch. Normally the instrument lighting shares the same circuit as the parking/valet lights.

The temp control lever or dial has a loose or disconnected vacuum line or control wire at the dash control or at the heater core valve under the right side dash or on opposite firewall in engine compartment.
listen for vacuum leak in dash. if you don;t hear it then you have to look for it follow line and also make sure the vacuum regulator is ok. You can check this by sucking and blowing on the line tube. You will know if its working when you do.

Also the control valve at the heater core can get stuck may need to lube it and manually free it up.
Hope this helps Mike

I generally agree with Tom. Further to that, if your car is running at a normal temperature by the gauge, I would most suspect your heater control valve. This is often connected by a cable to the dash control, and it can break or come loose.
.

verify heat is in normal range using dash gauge. if its normal then good. if it is below normal, you may have a sticking open thermostat not allowing heat to build up enough for "hot" heat. but usually luke warm heat will be this issue.

If everything is fine with gauge heat, check the hoses going to your heater core with your hands. they BOTH should be hot. If one is hot and another is warm then you have heater core issues. If both are HOT then you may want to check your temp controls. either temp control may not be working or the door that changes temp may be stuck in the cold position... there are many things, but checking the heater core hoses are most likely going to reveal bad heater core.

You will need wiring diagrams and volt meter to diagnose anything other than touching hoses and looking at gauge.

That was a good guess but if you temp gauge on the dash is normal then you don't have a bad t-stat. you probably have a bad heater control valve. It's what controls how much coolant goes into the heater core. Could also be a blend air door inside the heater box up under the dash. or a plugged heater core.

If all voltages checked ok,then most probably its faulty instrument cluster board on which gauges are connected.Yes if cluster circuit board looks ok,then also it can be faulty.Somewhere there is minute short or burn on board then such prolem arises.
Also check the fuse box.One under hood and other under dash.Inspect each and every fuse and see if all are fine or not.
---------------For more troubleshooting on these cluster gauges i suggest you to refer the list of help links mentioned below.Its step by step instructions will help you to confirm the exact cause of problem in these conditions:---------
Click the link below:------

2004 Toyota Tundra: Oil Gauge and Temp Gauge Not Working?

http://howtobyme.blogspot.in/2012/05/2004-toyota-tundra-oil-gauge-and-temp.html

--------------

2005 Lexus SC430: Fuel Door, Dome light and Fuel Gauge Fuse Location?

http://howtobyme.blogspot.in/2012/05/2005-lexus-sc430-fuel-door-will-not.html
----------

Toyota 4Runner: Temperature Gauge Sensor

http://technoanswers.blogspot.in/2012/04/toyota-4runner-temperature-gauge-sensor.html
------------

Temperature gauge sits over half way mark?

http://schematicsdiagram.blogspot.in/2012/04/temperature-gauge-sits-over-half-way.html

---------------

Heater blows intermittently and temp gauge goes erratic?

http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html

----------

Temperature gauge does not move and no heat when heater is ON?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html

-----------

2003 Pontiac Grand Prix: Erratic Fuel Gauge?

http://technoanswers.blogspot.in/2012/06/2003-pontiac-grand-prix-erratic-fuel.html

-----------

Temperature gauge keeps fluctuating up and down close to red?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-keeps-fluctuating-up.html

-------------

Temperature gauge on the dash quit working on Pontiac Grand Prix?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-on-dash-quit-working.html

---------------

Fuel gauge jumps from empty to full?

http://schematicsdiagram.blogspot.com/2011/12/fuel-gauge-jumps-from-empty-to-full.html

--------------

Gas gauge stuck on empty on 2002 Mercedes Benz 240c?

http://repairhelpcenter.blogspot.in/2012/02/gas-gauge-stuck-on-empty-on-2002.html
---------------

• Oldsmobile Temperature Gauge Lamp Switch?

-----------------

Fuel gauge drops to Empty?

http://technoanswers.blogspot.com/2012/01/fuel-gauge-drops-to-empty.html

----------------

Dodge neon gauges not working?

http://technoanswers.blogspot.in/2012/02/dodge-neon-gauges-not-working.html

------------

Temperature gauge went up?

http://schematicsdiagram.blogspot.com/2011/12/temperature-gauge-went-up.html

------------

Temperature gauge stays At cold on jaguar?

http://technoanswers.blogspot.in/2012/02/temperature-gauge-stays-at-cold-on.html
-----------

How to replace Instrument panel and dashboard on Toyota car?

http://repairhelpcenter.blogspot.in/2012/02/how-to-replace-instrument-panel-and.html

-----------

How to remove instrument panel on Chevrolet car?

http://technoanswers.blogspot.in/2012/02/how-to-remove-instrument-panel-on.html

-----------

How to remove control panel on Buick regal?

http://howtobyme.blogspot.in/2012/02/how-to-remove-control-panel-on-buick.html
---------------
These details will help.Thanks.

If all voltages checked ok, then most probably its faulty instrument cluster board on which gauges are connected. Yes if cluster circuit board looks ok, then also it can be faulty. Somewhere there is minute short or burn on board then such problem arises.

Also check the fuse box. One under hood and other under dash.

Inspect each and every fuse and see if all are fine or not.

---------------

For more troubleshooting on these cluster gauges I suggest you to refer the list of help links mentioned below. Its step by step instructions will help you to confirm the exact cause of problem in these conditions: ---------

Click the link below: ------

2004 Toyota Tundra: Oil Gauge and Temp Gauge Not Working?

http://howtobyme.blogspot.in/2012/05/2004-toyota-tundra-oil-gauge-and-temp.html

--------------

2005 Lexus SC430: Fuel Door, Dome light and Fuel Gauge Fuse Location?

http://howtobyme.blogspot.in/2012/05/2005-lexus-sc430-fuel-door-will-not.html

----------

Toyota 4Runner: Temperature Gauge Sensor

http://technoanswers.blogspot.in/2012/04/toyota-4runner-temperature-gauge-sensor.html

------------

Temperature gauge sits over half way mark?

http://schematicsdiagram.blogspot.in/2012/04/temperature-gauge-sits-over-half-way.html

---------------

Heater blows intermittently and temp gauge goes erratic?

http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html

----------

Temperature gauge does not move and no heat when heater is ON?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html

-----------

2003 Pontiac Grand Prix: Erratic Fuel Gauge?

http://technoanswers.blogspot.in/2012/06/2003-pontiac-grand-prix-erratic-fuel.html

-----------

Temperature gauge keeps fluctuating up and down close to red?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-keeps-fluctuating-up.html

-------------

Temperature gauge on the dash quit working on Pontiac Grand Prix?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-on-dash-quit-working.html

---------------

Fuel gauge jumps from empty to full?

http://schematicsdiagram.blogspot.com/2011/12/fuel-gauge-jumps-from-empty-to-full.html

--------------

Gas gauge stuck on empty on 2002 Mercedes Benz 240c?

http://repairhelpcenter.blogspot.in/2012/02/gas-gauge-stuck-on-empty-on-2002.html

---------------

• Oldsmobile Temperature Gauge Lamp Switch?

-----------------

Fuel gauge drops to Empty?

http://technoanswers.blogspot.com/2012/01/fuel-gauge-drops-to-empty.html

----------------

Dodge neon gauges not working?

http://technoanswers.blogspot.in/2012/02/dodge-neon-gauges-not-working.html

------------

Temperature gauge went up?

http://schematicsdiagram.blogspot.com/2011/12/temperature-gauge-went-up.html

------------

Temperature gauge stays At cold on jaguar?

http://technoanswers.blogspot.in/2012/02/temperature-gauge-stays-at-cold-on.html

-----------

How to replace Instrument panel and dashboard on Toyota car?

http://repairhelpcenter.blogspot.in/2012/02/how-to-replace-instrument-panel-and.html

-----------

How to remove instrument panel on Chevrolet car?

http://technoanswers.blogspot.in/2012/02/how-to-remove-instrument-panel-on.html

-----------

How to remove control panel on Buick regal?

http://howtobyme.blogspot.in/2012/02/how-to-remove-control-panel-on-buick.html

---------------

These details will help.

Thanks.

These lights for the dash are controlled by a rheostat instrument control dimmer switch next to the main light switch for the headlights, it is either turned off (have seen this dozens of times) or it is defective. Below is a picture of the switch assembly I speak of. The thumb wheel next to the knob is the dimmer control.

The BCM is located immediately above the heater controls inside the dash on my 2004 Astro. I know it controls the headlights and locks but not gauges. Haynes says the gauge fuse supplies it power....but I'm not going to bank on that one.

P/N 15081796 from Napa $115

Good Luck

good be dimmer switch, but only if all dash lights are out,like radio heater control, cig light,if those still work then i would say its bulbs.