headlights work but, running lights don't,bad switch or ground???

What kind of vehicle?

running lights = taillights?
Do you have 12 volts at both ends of the taillight fuse?

Check at the fuse holder clips because many times the fuse doesn't make a good connection with its clips.

69 chevelle, no sidemarkers or tailights, just headlights

also no dash lights!!!

tried a new switch, that didn't work

Did you check voltage at the fuse clips yet?

The dash light fuse gets its power from the taillight fuse to alert you that your taillights might not be working.

I have voltage at the fuse clips

I disconnected the switch from the harness and jumped power on the harness to the dash lights and sidemarkers on the harness and they all work,does that mean my switch isn't getting a good ground??

even if you have a ground problem you will still have hot to the bulb sockets. its worth a try grounding the switch and the back of the guage cluster.

first thing that comes to mind is to make sure the connector for turn signal switch is nice and tight (presses together) so that all leads make contact. i have had this happen on my 68 only to find not all wires were making contact at the connctor of turn signal switch at base of steering column. if switch was bypassed to give direct power to dash and marker lights -and they work- i would suspect the switch is not getting power. chk for 12 volts at the red wire on the light switcn connector. 69 diagram shows that red wire goes to the battery. make sure all fusible links look good (not rubbery or burnt) at j-block next to battery. all fuse look good according to postings -that good. i would also suspect the turn signal switch -a major player in this circuit/loop just like the headlight switch. aside from that, all switches and lighting should have good grounds although i dont suspect ground issue at this time. post any findings, be real specific, we'll get u through this.

put my key in the ign. and jiggled around and lights came on

back to not working again

1. The taillight and side marker light circuit does not go through the ignition switch or the turn signal switch so those two switches have nothing to do with the problem. I can't see how the taillights coming on when you jiggled the key can be anything but a coincidence.

2. A ground or no ground AT the headlight switch has nothing to do with the taillights or marker lights, they get their ground at the taillight mounting.

If you can get the lights to work by jumpering the headlight switch contacts, the problem is in the headlight switch, either that or just moving the wires around while doing it causes a broken wire to make connection.

The dash light power feeds off of the taillight circuit so if there is no power to the taillights, then there is no power to the dash lights either.

I decided to check my fuses for a third time, and when I went to pop it out with my mini screwdriver there was a small spark, as if It wasn't getting a good connection , so I pulled It (acc) out and put some di-electric grease on both ends and as soon as I put it back in all my lights came on!!! Thanks for all the help guys!

I decided to check my fuses for a third time, and when I went to pop it out with my mini screwdriver there was a small spark, as if It wasn't getting a good connection , so I pulled It (acc) out and put some di-electric grease on both ends and as soon as I put it back in all my lights came on!!! Thanks for all the help guys!
Hmmm, it had to have been making a connection or you wouldn't have had 12 volts at both fuse clips like you said you did have.
I have voltage at the fuse clips