Hello everyone, first post.

I've been successful so far finding out how to do stuff to this little beast by just searching, but this problem is stumping me.

My pickup is a 1989 2wd with a 2.3 liter and manual 5 speed.

When the lights are off, the brake lights light when the pedal is depressed like normal. Turn on the lights, and I get tail lights like I should. But the brake lights will no longer light if the rest of the lights are on. Basically, all the lights function as they should, until I apply the brakes at night with the lights on. Then I do not have brake lights.

I thought maybe someone had replaced double filament bulbs with single filament, but seems the sockets cannot be removed from the housing to check the condition of the bulbs? The tail light socket has 2 wires whereas the turn and reverse sockets have one wire, leading me to make the assumption that the tail light bulb is double filament.

A search for images of tail light housings has shown me that replacement units come with sockets and wiring already installed.

Does the failure of one bulb really force you to replace an entire tail light assembly??? Wouldn't surprise me one bit in a vehicle newer than 2010, but in a 1989 you'd think you could replace individual bulbs?

 

Ok, I figured out how the tail light lenses come out (duh - never seen one like that) and subsequently was able to put a meter on my bulbs and determine that they were still good on both sides, and I had 12vdc to both terminals at the right times.

Here's where it gets weird...

With the lens out I was able to see that the bright half of the bulb was coming on with the lights, and the dim half was lighting with the brake pedal. So of course I couldn't see the brake lights light up, they were "overpowered" by the brighter half of the bulb (and why I could see brake lights with the lights off) Visually all the wiring matched (color-wise) so I got to thinking that a previous owner had crossed things elsewhere in the wiring harness. Rather than search all over for that, I just cut the two wires to each socket and switched them with butt connectors. Now the dim half of the bulb comes on with the lights, and is "overpowered" by the bright half of the bulb when the brakes are applied. Go figure...

I guess I jumped the gun a little with this post - but it does give me the opportunity to say "thank you!" to everyone who is here regularly and takes the time to post valuable information for others. I've learned a lot about my little old friend from y'all, and I appreciate it!