This started when I changed my running light bulbs the other day. The driver side was blown and the passenger side was real dim. So I bought a pack of new bulbs and swapped them out. I noticed they were considerably brighter and the volt gauge was reading higher than 14 volts. Now the bulbs are both blown, and the volt meter is still reading high. I have checked the bulb sockets and wiring and see no issues. Any ideas what to check next?

 

voltage regulator on alternator? Probably not your case, but I had a similar issue with blowing headlight bulbs. I did not check voltages so I can't compare them to your results. Turned out to be mud caked on the connectors and the bulbs themselves causing some sort of a short. I cleaned them off real good, and haven't had a problem since.

 

on my 80 the VR went our (external regulator) and blew all of my bulbs except the headlights. i had like 34 v in the tail light sockets

 

Where is the VR located on these trucks?

 

disregard the voltage regulator inside the alternator. Not sure if those 83's had the integrated VR or not.

 

I'm gonna try another pair of bulbs but I doubt anything will change. I have a Fluke and can test it but wanted to see if there were any particular electrical problems these trucks were known for.

 

Earlier today I checked the bulbs I had taken out and one was a 63 and the other a 67. The 67 was the one that had not blown originally, I just didn't check the number and simply bought a replacement for the 63 that was blown. So I bought some 67s and now everything is working.

My volts are reading 14 on the Fluke. Not sure if that's too high as I thought most auto DC was supposed to be 13.7.

 

14 is fine. Pretty dang good if you ask me.