79 308 w/no power to frt rt signal or parking light

For the "positive" voltages, the RH front turn signal and the RH front parking lights don't really share anything electrically other than passing thru the same connector at the RH front lamp assembly so it's unusual that the "+" power for both would be "bad" together. They do share a common ground, but since you say that the ground is OK, it seems odd that that isn't the culprit.

Have you tried making a direct voltage measurement:

1) between the A (light blue) wire in the connector on the harness side and a known good ground (like the "-" battery terminal) when the RH turn signal (and key) is (are) "on", and

2) between the G (yellow) wire in the connector on the harness side and a known good ground when the parking lights are "on"?

PS The flasher flashing quickly when the RH front turn bulb isn't working is a natural consequence -- the same thing happens when any bulb (front or rear) on a side is blown or not working.

 

Mine had same problem. My easy fix was cleaning the ground wire on the backside of light and then it worked fine.

 

If you need a new turn-signal assembly, PM me. I have one left. My old one had one of its wires sheared off from corrosion, vibration, and old-age.

 

I think the fact that the relay clicks once and then not again, with only the rt frt blinker and parking light not working is purely coincidence. It is interesting info however.

My blinker relay does the same thing. (only clicks once.) But all lights work appropriately. The hazards click all the time. (separate relay).

I would press on with tracing the wires as best you can and check for clean connections. The ground was my first thought as well.

On mine, I wound up having a broken ground wire. I ran a separate wire to the ground post inside the fenderwell, behind and right next to the right hand headlight actuator. That seemed to fix the problem for me.

But then you said your ground was good. So I'm at a loss other than thinking that it could be two broken wires inside your harness forward of the fuse box.

Good luck.