I've got a 94 bronco with one of those overhead displays that shows the temperature and has a compass. But the only thing that actually works up there is the compass. The temp will usually display something at least 10-15 degrees hotter than it really is, and usually something higher. I could be wrong, but I'm pretty sure it didn't hit 129 in Salt Lake the other day.

I'm wondering if anyone else here has had that same problem? I'm thinking it might be a matter of moving the temp sensor for that display to somewhere that's a little cooler, but I have no idea where that thing is, or how to get to it.

If anybody has any ideas or info I'd appreciate it, but if not, it's no big deal. I don't really need my truck to tell me it's hot or cold outside. I can usually figure that out on my own. It's just one of those stupid little things that begin to bug you after a while.

Thanks- ferris

 

Im not sure on broncos, but I know on most vehicles that the sensor is located between the grill and the radiator. Im guessing that the sensor just went bad, shouldnt be hard at all to replace.

 

I was looking into this and found a tech bulletin about this. There is a upgraded harness and module for the 94-95 trucks. If I have time tody I will find it at work and post the bulletin number and part numbers. It adds a wire to move the temp sensor ground from the radiator support to the module, and a new temp/compass module. Only problem is when I called the dealer about it, it was still instock, but the cost was around $300 dollars. Or maybe it could just be the sensor on its way out. Those are cheap I just bought one for $29.

 

Steve has the sensor loc. diagram here:
http://www.superford.org/registry/ve...id=72378....he may have the stuff u need

 

Thanks guys! I love this place! This was my first post for a question because every other question I've had has already been answered in other posts. I posted this last night before bed, and I've already had help from you guys. Thanks again!

 

The thermometer actually reads the ABS sensor on the rear axle and modifies the value it displays based on how fast you're going and how long the engine has been running/off. I'll try to post the info here, but if there's too much text, just e-mail me & I'll send you the document.


Compass/Outside Temperature Display

The overhead console is a multifunctional unit. Contained within the console are two independent map lights that also function with the courtesy lighting system.


Compass/Thermometer Display, Sensor and Wiring

A directional compass and outside temperature display also are contained in the overhead console. The display dims correspondingly with instrument panel illumination lamps

An opening door on the console provides storage space and can house a garage door opener.


The compass system consists of an electronic compass transducer and the overhead console to display the direction.

The digital compass will be displayed when the MODE button is pressed. The current vehicle heading will be displayed as one of the following directions: N, NE, E, SE, S, SW, W and NW.

Display Proveout

Verify that following display actions occur in order when the key is switched to RUN:
1. All segments light for approximately one second.

2. All segments go blank for approximately one second.

3. Compass then displays directional heading.

Factors Affecting Accuracy

Various internal and external conditions can affect compass accuracy.

· Magnetic mount devices (antennas, racks, etc.) should not be located near the magnetic sensor. Use of these devices near the sensor will cause the compass to be inaccurate. If these devices must be used, the compass should be recalibrated using the zone and calibration adjustments.

· Driving near power lines or objects with high iron or steel content (bridges, underground pipes and tunnels, etc.) may temporarily change the compass heading. The display will return to the true vehicle heading after the vehicle leaves the area.

· In most locations, magnetic north differs from the "true north" direction shown on maps (geographic north). This difference changes considerably across the country anywhere from 25 degrees to the east to 30 degrees to the west. This misalignment can be corrected on the compass by performing the Zone Adjustment procedure.

The temperature display operates through the use of a thermometer sensor (15A022) mounted behind the front bumper/grille. The display can be changed from English to metric units.

To update the temperature, the module processes data from the sensor to make sure engine heat does not affect the displayed temperature. Upon starting the vehicle, the module checks the temperature and how long the ignition switch has been off. These parameters are described by one of three groups below.


Engine Cold

If ignition has been on for less than five minutes, and was previously off for longer than two hours, the engine is cold and does not affect the temperature sensor. Current sensor data is used.


Engine Warm, Updated Temperature Cooler

If ignition has been on for longer than five minutes or if the ignition was off for less than two hours, the engine compartment may be warm from the heat of the engine. The current temperature is displayed only if it is less than the stored temperature reading.


Engine Warm, Updated Temperature Warmer

If the sensor data indicates a higher temperature, the module uses a high-speed counter to monitor vehicle speed to determine whether engine heat is causing erroneous readings. The counter is incremented when the speed is greater than 53 km/h (33 mph) and decremented when the speed is between 16 and 53 km/h (10-33 mph). If the speed is less than 16 km/h (10 mph), the counter is reset, and the displayed temperature is not updated from its last reading. If the counter is greater than two minutes, the currently sensed temperature is displayed. If the high-speed counter has counted less than two minutes, the temperature can increase only one degree per minute.

If the temperature sensor is short- or open-circuited, the display will read SC or OC, respectively. If the temperature drops below 3°C (38°F), or is below 3°C (38°F) upon power-up, the display will alternate between displaying ICE and the temperature. The display will alternate every two seconds for a time of one minute.

Zone Adjustment

The vehicle has been demagnetized and the compass calibrated by the manufacturer. However, the zone adjustment is not done by the manufacturer.

When the vehicle is received from the manufacturer or whenever a vehicle operator claims that the compass is inaccurate, first perform the zone adjustment. The compass zone adjustment is as follows:

1. Determine which zone of the continent you are in by using the accompanying zone map.


2. Press and hold the MODE button until VAR appears on display. The overhead console will display the current zone number.

3. Press the MODE button until the appropriate zone number appears on the display. (The zone number will increment once each time the MODE button is pressed. Once the number reaches 15, the next press will change the zone to 1.)

4. Release the MODE button and after a few seconds the display will return to the normal compass heading mode. The zone adjustment is now complete.

Calibration Adjustment

The compass is designed to recalibrate itself if changes in vehicle’s magnetic field occur.

Occasionally, the vehicle’s magnetic field will change enough to prevent the compass from correcting itself. If the preceding zone adjustment does not correct an inaccurate compass, the compass should be calibrated. If a compass transducer unit is newly installed in a vehicle, the calibration procedure must be performed. To calibrate the compass, perform the following procedure:

1. Find an open area free from steel structures and high voltage lines.

2. Press and hold MODE button until the CAL indicator appears in the display.

3. Release the MODE button.

4. Drive the vehicle less than 8 km/h (5 mph) in 360° circles until CAL indicator turns off. This will occur within 2 to 3 complete circles. Each compass heading quadrant is greater than 35 degrees and less than 55 degrees wide.


Vehicle Demagnetizing

If the compass is inaccurate after calibration, vehicle magnetism may be too high and vehicle demagnetizing is necessary. Initially the vehicle is demagnetized at the manufacturer's plant. In most cases this is sufficient for the life of the vehicle. However, if after calibration the compass still is inaccurate, demagnetizing must be performed.

Note:
The demagnetizing procedure must be followed exactly. Failure to do so may result in the vehicle being remagnetized.

Note:
Whenever the demagnetizing equipment is being operated over the vehicle's surface, or within 1m (3 ft.) of the vehicle, the operator must maintain a constant, steady motion. Failure to do so may result in the vehicle being remagnetized.

The demagnetizing process requires the use of a demagnetizing coil commonly used by TV service technicians to demagnetize television tubes. Demagnetize the vehicle by sweeping over the compass sensor with a demagnetizing coil as follows:

1. Standing 1m (3 ft.) or more away from the vehicle, turn on the demagnetizing coil.

2. In one continuous motion make four passes over the compass sensor. The demagnetizer should be held 2-1/2 cm (1 inch) or less (but not touching) from the vehicle's roof.

3. After the fourth pass, and without stopping the motion of the demagnetizing coil, pull away from the vehicle.

4. When the demagnetizer coil is at least 1m (3 ft.) away from the vehicle, turn the demagnetizing coil off.

5. Perform the Zone Adjustment and Calibration Adjustment procedures.