Tac-20

Hi all. Has anyone heard of a tac-20 not answering hall calls when in viscosity mode?

upgrade your software or turn viscosity off

I couldn't find a parameter to disable viscosity. Only to choose viscosity floor return.

Nope not that one. Heard and seen where the car wouldn't answer hall calls when seemingly on auto, but toggling fire ks to bypass then off took care of it.
Did you actually see/prove it while in a diagnostic mode with the laptop?

It never showed any faults when hall call registration went out after around 4-6 seconds. You can give it car calls from laptop. And doors will open. Problem occurs while on viscosity only.

Viscosity is done with the red and yellow wires, bottom right side of the board. Yellow wires are for the "set" temp, red are used,for "over temp". Both yellow and red will have wires going to a common, simply remove the yellow wire from the common and you will no longer have viscosity, yet you will still have over temp protection. *had a thought prior to hitting enter, double check that red is going to over temp and yellow is going to set. Believe it is OLTS for set, and OLTO for the over....wonder if instead of commons landed, if they landed two wires on the OLTO if it would ignore hall calls....*

The parameters cannot be changed to remove it, and there is nothing that I can remember about any sort of inspection mode when on viscosity for those units. Make sure some mechanic didn't add a relay in there. Only thing I have seen that is remotely close to this is jack resync. When car has begun resync operation it ignores hall calls, but still responds to car calls.

Thanks for all the help guys!!! Appreciate it. I'll check for added relays .

Tac 20's that were installed on my route in 2012 had this problem. It was software related and the adjuster installed some as yet un-approved software that he got from an engineer at TKE that solved the issue.

Thanks for the info Dan!!