'84 60 Rear lights not working w/ headlights

[psulick3]

As title states, my rear and side lights are not coming on when turning on headlights. Taillights work fine under breaking but not when headlights are on. I checked the TAIL fuse in the fuse box and that isn't it. Anyone have any troubleshooting suggestions on where to start? Thanks!

 

[dmjay]

Start with a multimeter.

 

[panchovilla]

As title states, my rear and side lights are not coming on when turning on headlights. Taillights work fine under breaking but not when headlights are on. I checked the TAIL fuse in the fuse box and that isn't it. Anyone have any troubleshooting suggestions on where to start? Thanks!

I am having this same issue, did you find the problem?

 

[psulick3]

I am having this same issue, did you find the problem?

Yep, relays under the dash. I pulled the headlight relay and plugged it into the tail light relay slot. Everything worked fine (except the headlights obviously). Bought a new relay and bingo. Just mad at myself for not having tried something so simple sooner.