Ohh...you had 1156 bulbs in (single 27w circuit) where there should be a 1157 (5/27w twin circuit) bulb? Right?
Wanted to give u better answer. On my 95, imagine the tail light connections with no bulbs. The top one (brake,turn signal) has 2 little brass looking metal "pods" that are slightly raised in order to make contact with the bulbs MATCHING 2 "pods"......thus both sets of raised "pods" are touching and in theory should work at that point. (assuming nothing else is wrong) Right?? Right!
However, apparently one of two things happened.
1) Way back I bought the wrong bulb because I also took apart the LEFT tail light assembly just to put my eyeballs on the WORKING side to see if I could tell any difference. I pulled the LEFT (working) bulb out and compared it to the RIGHT side bulb (the one not working) and I noticed a very slight difference in the size of the metal end "pods"
The ones from the working bulb were slightly larger and more raised than the non working bulb. So I put the left side bulb in the right side tail light and immediately it worked.
SOOO.... either I bought the wrong bulb several years ago...OR...just by wear and tear the right side bulb "pods" had been rubbed down to the point they no longer made good contact.
Now imagine the lower connection (reverse light) with no bulb.....
That connection only has ONE "pod." Not 2 like the brake lights do.
However, the bulb I had in there had TWO "pods"....
The single pod on the connector would sometimes make contact with the two pods on the bulb, sometimes it wouldn't.
In short, I had a brake light bulb in the reverse connector. Not good. lol.
So I bought 2 new brake lights and 2 new reverse lights, some grease, made sure I put the right bulbs in the right places, (changed all of them), put everything back together and BINGO. Works like a charm now and I'm happy to report that I passed my inspection today. However, and I'm not making this up....the person first told me he couldn't pass me because "none of your brake lights or turn signals work," And I was like OH HELL YES THEY DO, LET ME SHOW YOU!!!! He agreed, I climbed in the cab turned the power on and went through every light and they all worked just fine....just like I said they did, but better yet, KNEW they did. Then I passed.
I hope this answered your question better.