ERA 427 S/C turn signals

[DonC]

My ERA has the 4 tail light setup. I had to remove them to have some rear fender damage repaired and after I reinstalled them the driver side rear turn signals don't work. The passenger side work fine.
All the other functions of the lights are working, marker and brakes and the front turn signal also works.
Putting a voltmeter on the yellow leads on the driver side gives me a slightly lower voltage reading than on the passenger side. I swapped one of the fully functioning tail lights from the passenger side to the driver side with no luck.
As near as I can tell there is a voltage drop on the driver side. Voltage on the passenger side shows about 10V and the driver side about 8V. Pretty hard to get a decent read with a digital VM when the power is only there for the cycle time from the flasher.
Looking at the wiring diagram leads me to believe that the voltage drop may be coming from the tail light relay. I'd like to replace it but not sure how to remove it. Is it a plug in module or is it wired in? Can't really get a good look at it as it seems to be mounted above the 2 fuses in the holder under the steering column.
Has anyone every replace the tail light relay on a 427 and if so how did you do it?
Any suggestions would be appreciated.
DonC