I have a 98 Tacoma. The HVAC control unit has two #74 bulbs in it. I went into mine to replace one that I thought was burned out and it turns out the socket is bad. Anyone know if these sockets are serviceable or do I need to replace the entire control unit just to get the bulb working again? I have not removed the control unit, but its the upper right bulb and it looks as if the socket is built into the unit.

Anyone had any similar issues before?

 

Upon closer inspection it looks like the socket is removable. You twist in 90 degrees and then it pops out the back of the control unit.

I removed it and then tested the socket with a voltmeter and it has 12 volts, although when I plug in a bulb it does not work. I think I just need to mess with the contacts to get them to seat better with the bulb. If I can't make it work reliably, looks like an easy fix to replace the socket.

 

I've been having trouble with mine in my 4runner for years. The LED bulbs are too loose in the sockets so I decided to just put in regular 74 bulbs and they seemed to be too big and I still don't get good contact to light the display. Right now I'm just rolling in darkness until I figure something out when the weather is nice enough to dig into it. I'm really considering building a PC board of LEDs to lay over the controls and behind the display, no hot spots from only using two bulbs and no messing with #74 bulbs anymore! Easier said than done though.