1965 C10 Indicators

[dkerr]

I have an issue with my indicators that I cannot find a fix for.

When I use my lights normally, including brake lights, all is good until I go to use the indicators and this fault happens whether the lights are on or off.

The front indicators work normally when used as do the indicator lights on the dash but the rear ones flash together like a hazard light. When it is doing this and I put my foot on the brake, the brake lights work and the indicators stop and the indicator lights on the dash and on the front (no matter what side I am using) stay on solid, as soon as I release the brake pedal the indicators operate as above.

I have installed a new wiring harness (complete plug and play type) and have checked the connections. I have two switches and it does the same with both.

Are there any auto electricians out there who may be able to help, please.