90-96 Photocell Repair
Figure 1 - DIC Overview
Dimmer Circuit Behavior
With the headlights off, the headlight dimmer control has no effect - the Photocell alone controls the brightness of the cluster. The bulbs should be at full brightness on a sunny day, medium brightness on a cloudy day, and low brightness at night or when the photocell is covered.
With the headlights on, both the headlight dimmer and the photocell control the brightness of the cluster. In general, the bulbs should be at full brightness on a sunny day, medium brightness on a cloudy day, and low brightness at night or when the photocell is covered - plus or minus any adjustment dialed in via the headlight dimmer. The headlights should dim when the headlight control is rotated to the Dim setting, and should get brighter when it is rotated to the Bright setting.
It's easy to replace the photocell sensor. Partial disassembly of the Digital Information Center will be necessary, and it will be necessary to solder two large solder connections, but the skill required is minimal.
What you'll need to service the Digital Cluster
Photocell Kit from batee.com - Click Here
Small drill bit or Xacto knife to remove factory photo cell from its housing
A small Phillips screwdriver
A T15 Torx Driver bit and handle
A Soldering Iron (Radio Shack has these for $8.99 as of 2014)
A way to desolder - use desoldering braid from Radio Shack if you don't have a preferred method
Warning! Disconnect the positive battery cable before disconnecting the Digital Info Center. Failure to do so will set codes related to seat belts and INFL RESET lamps!
Disassembling the DIC
Figure 2 - The Photocell
- Carefully remove the ribbon connector from the rear of the DIC
- Remove the four T15 screws from the front and set the metal frame aside
Remove the fifth T15 screw from the rear, then remove the black button assembly.
- Remove the six Phillips screws from the rear of the button assembly and separate the halves of the black case.
- Carefully unclip the photocell circuit board from the black case to expose the solder joints of the photocell.
- Desolder the photocell connections and remove the photocell and light guard assembly.
- Use an Xacto knife to remove any glue that might be holding the photocell inside the housing. Then remove the photocell from the cylindrical black housing.
Insert the new photocell into the black housing with one lead in each hole in the plastic housing.
Insert the two leads into the board and solder the photocell in place. Trim away the extra length of photocell leads with the wire cutters.
Reassemble the Digital Information Center by reversing the disassembly steps above.