Hi guys, I'm good with mechanical but not good with electrical so hoping someone can help.

Check the earth (ground)

Give us a look at your bike

if you have power to both terminals in brake light and brake light works cant be bad earth must be a contact problem with  the terminals, could have worn from vibration and only have good contact with brake light circuit, test with wire and bulb to see if it illuminates with wire touching taillight circuit make sure you earth the remote bulb.

I'll give all suggestions a go before I trundle down to an auto elec and pick their brains. I'll let you know what I find. Here's my old girl. Bob Woods W6 camshaft, cam bearing upgrade, S&S steel breather gear, Screaming Eagle lifters, Screaming Eagle adjustable pushrods. Only ever use Amsoil synthetic oil. To me, this is the best looking bike HD have ever built and this bike will never leave my hands. Ride safe and have a great Christmas everyone.

this might help,how bright is your stop light?.you may have a poor/no earth,in which case the stop light can earth back through the tail light circuit.it will have a weaker glow due to resistance in other globes in the circuit.but as you only have one stop light and in an incomplete circuit stop light switch open]the tail light will not work or only lightly glow and may not be visible through the lense.this is not always the case ...but sometimes.cheers

Hi Bill
I doubt the trip meter  has anything to do with your tailight problem.
It sounds like the wiring is ok and you have a problem with the bulb fitment in the socket.
Don't know all the correct terms, but in the base of the socket there is a round piece of insulating material in which are seated the two contacts on the ends of the stop and tailight wires.
There is a spring behind this which maintains the contact against the base of the bulb.
Put your finger in the socket and give this piece a push to ensure it can move in and out through its travel range.
The insulating material has two small tabs at 180° which locate in the sides of the socket.
Sometimes these can be a bit worn and the contacts will not locate correctly in the base of the socket or they will rotate slightly when the bulb is pushed into place.
I also found that the orientation of the contacts on the base of the globes can vary a little bit and some seat better than others.

I have switched to an LED talilight bulb.
1157 BAY15D LED replacement
These are much more durable  than the standard globes which suffer a fair bit from the suspension.

Don't have too many pictures of my bike

here is one stock when I first got it

here is current after a bit of work

SE heads and 10.5:1 pistons, SE 57 cam, S&S lifters and Andrews pushrods, 95 HP, 150 rear tyre and black paint

Meanmother57 ws right. It was a corroded terminal inside the Deutsche connector. There was enough power getting through to register at the terminal but not enough when you put a load on it. Terminals cleaned and problem fixed!