What is this? 96 Bonneville dashboard sensors.

[jmulhearn]

I have a 96 Bonneville SE with the electronic heat control and I am wondering what are the
two sensors that are inserted in the top of the dashboard.
They are both on the top of the dash (above the gauges). The first is in the center, close to the windshield, looks like a large jellybean inserted in a hole. I believe this one is the interior sensor that is used to determine the cabin temp.
But the other one has me stumped. It is about even with the steering column, about halfway between the windshield and the front edge of the dashboard. This one looks like a round cover, about the size of a nickel, even with the surface of the dashboard. What is this for?
I am having issues with the heater in this car and it seems that the source of the problem is the Heater control behind the glove compartment. Could one of these be the problem??

Thanks for reading this, any help is appreciated.

[nos4blood70]

I believe one is the twilight sentinel, which measures ambient light to know whether to turn the lights on and off. I'm clueless as to the other. I'll let the 92-99 guys chime in.

[John Deere Boy]

The one in the center that looks like R2-D2 is the solar intensity sensor for the climate control. The actual cabin temperature sensor is behind the vent next to the cigarette lighter. You might pull it out and make sure it's not clogged or dirty, but i've never heard of this being a problem. The larger round sensor on the left side of the dash is the light sensor for twilight sentinal. Cover it up and the lights will come on in after several seconds.

[bsan63]

How would you go about testing the Solar Intensity Sensor or is there even a test for it.

[jmulhearn]

Thank You Very Much for the info, I really appreciate it. I'll check these out.

[John Deere Boy]

The electronic climate control has it's own onboard diagnostics and trouble codes and should be able to detect a bad sensor, but unfortunately for 1994 and newer cars, you have to have a scan tool to get these codes. On 94+ cars, i think the temperature display blinks if a code has been stored.

The air mix door actuator is a common thing that fails. It controls how much air goes through the heater core vs. evaporator. It is an electric motor that drives plastic gears, and the plastic gears are known to crack. Check this out: http://www.pontiacbonnevilleclub.com/fo ... c3537.html

[jmulhearn]

Yes, my Temperature display blinks when I first start up. Does this mean that the air control is bad or the sensor is bad?
???

[John Deere Boy]

It means that you have a diagnostic trouble code. Gotta have a scantool to find out what the code is. I dunno if autozone's scan tools can read ECC codes or not, but i kinda doubt it.

My money is on your air mix door actuator. Read through that link i posted and see if it fits your symptoms.

[jmulhearn]

My bet is on the air mix door being faulty.

I'll have it looked at probebly next week and let you know.


Thanks for all your help, time and knowledge, I appreciate it.

[ga93sle]

The little info I've read here sounds exactly like what my 97 SSE was doing. Was the airmix door.

[jmulhearn]

This car never ceases to amaze me. Now, on the floor on the passenger side, I found a quarter size half moon gray plastic gear. It does not appear to be damaged in itself but my money is that it is from the air mix actuator.
This car is like a cartoon, pieces falling out as it goes down the road. Well, it is something else for my collection of car momentos. I have the hood ornament from a 86 Buick Wagon, that was all that was left from an accident.

[Sirius]

Now, on the floor on the passenger side, I found a quarter size half moon gray plastic gear. It does not appear to be damaged in itself but my money is that it is from the air mix actuator.

That would be kinda difficult, since the motor and gear drive are enclosed in a case that is screwed together. Can you post a picture of the gear you found?

[jmulhearn]

I really hate computers sometimes. I've bben in the IT field since 1967 and I trully dispise these hunks of wire and plastic.
I tool 3 pics of the gear I found (out of foucus because my camera can not focus closer than 3-4 ft) but I can not find a way to copy and post the pic here. I'm sure there is a way but the magic escapes me.
The gear is just larger than a quarter, Half moon shape,the teeth on the outside with a 'slot" going from the center (flat side) on a 45 degree angle 2/3 way thru toward the teeth.

Well. hope this helps. Thanks for your time, I really appreciate your help.