dash lights stay on

[jblueridge]

'88 BJ74 24V Dash lights come on as normal when I am turning the key to start the truck.
The lights stay on after releasing the key when engine is running. see photo below.
I checked battery terminals and main ground. Nothing funny there.
Anyone seen this before?
Thanks.

 

[jblueridge]

Checked the Engine and Charge fuses. They are okay.
I took the drivers side dash apart and removed the gauge cluster. Electrical terminals look fine. Nothing else to see. Reassembled it. Lights still remain lit.
Removed kick panel and found the ground point above and slightly rear of the fuse box. Unscrewed the bolt there and polished up the body metal and the almost rectangular "ring" terminal the 2 ground wires are crimped onto. Re assembled: dash lights stayed on.
Tested alternator output voltage and found it was 24V.. Manual says it should be 27V at idle. Replaced external voltage regulator with new OEM. Lights still stay on.

Not sure how to test alternator current output... one of those clamp meters?

Any ideas welcome.
Thanks.