Hi,
The "Jacks down" light is actually a fluid level switch, that thinking is when the fluid is in the jacks, they 'are down'. Unless the fluid shrinks and has less volume when cold, or there is a leak in one jack seal, and the fluid will never return, while all the jacks are really up.
As the engine warms, in my case the reservoir is close enough that it will warm the jack reservoir, and will indicate jacks up after a short drive.
Be sure to visually check the jacks are up all the way. If you need to, add 1/4 quart of transmission fluid, and then the 'jacks up' indicator will be happy, and the light will turn off.
Yes hydraulic fluid does move slower on cold days than warm ones, but still the jacks should retract in a few seconds, cold or not.
One time I had a leaking seal, and did not have any transmission fluid with me to put in the reservoir. So I had to find the tiny 10 amp fuse going to the reservoir switch, pull it out, and then could drive on, without the beeping and light flashing. You might want to locate that fuse, so you can pull it in the event of a low fluid level, and you are miles from anyplace!
Good luck,
Fred.
