I woke up this morning to a -40 windchill. The autostart on my Buick Lucerne did not function. The car battery is under the Rear seat. I bought a battery warmer pad but I’m unsure as to how to wire it to the outside. Any ideas?
How old is the battery? Batteries don’t care about windchill, only real temps, and it’s only -12 up there. I’m guessing you need a new battery rather than heating it.
Haven’t ventured out to try the key… Still want to put a heater on the battery… works great for my van…
If you park inside you can just leave the drivers window down an inch with the extention cord through it. I would do the drivers window, so you cannot forget and drive away with the cord still in the car.
If outside just pinch the extention cord in the door as you close it. The door seal will give enough flex to not damage the cord. keep it in the bottom rear corner, where there is less stress.
Yosemite
. @Shadowfax is right and that temp can still be dealt with a good battery. Though I see nothing wrong with "heating " a car up before starting it with a device, I would do it with an engine warmer and not a battery warmer. A trickle charge with a battery in good shape to ensure you have enough stating power will also supply a residual amount of heat which you could then supplement with any in line heater to heat the block. It requires less stating power to turn over an engine whose lubricating oils are warm and your motor will run better sooner which is important in getting heat to the cabin and making your car “last longer”.
I’ve heard of people taking out the battery and bringing it in the house over night, but I think that would only be needed with a battery that’s on it’s way out already.
I too think a block heater would be better. I had many years ago and I even know I have one in a drawer somewhere in the shop.
I remember years back on the farm, and we would drop the trouble light under the hood and let it hang. Then a couple of old quilts were thrown over the hood that had each corner weighted down.
Over night it would keep the air a little warmer the old trucks would start right up.
I doubt that it helped to heat the engine…but drawing in a little warmer air when starting seemed to help.
Yosemite
How about digging an open pit and dropping in a bag of charcoals, lighting it up then parking the car over it at night ?
I did that once too Dag. It worked, but I only slid a shallow pan of coals under the engine…not a whole bag. Had to save something for the steaks.
Yosemite
I have heard people doing it but I have this fetish of about not leaving an unattended Fire under a car. So, let me add, “in jest”. 
I’ll never forget one week of my life when I was in my 20s living in WI. It was the middle of winter and my car snapped a camshaft. I had to ride my motorcycle to work for a week. 20 miles one way. Being a warm blooded machine, it had no chance of starting in -10F weather. So I had to light charcoal in a hibachi in the morning and put it under the engine while I bundled up for the trip.
Nothing like going over the high rise bridge with a couple of inches of snow on the road. The force of the cross winds and slippery conditions made the bike change lanes unexpectedly.
I also discovered that it was a degree or two warmer following 10’ off a semi bumper 
By the time I warmed back up, it was time to drive back home!
It is an outside car. We moved up here from Delaware July of 2013… The first sub-zero night was -27 (not wind chill) My little ford focus would only groan… The hood cable was froze, so I had to bring out a ready heat kerosene blower and put boxes around it to create a wind tunnel into the grille… Finally the hood released after 20 minutes. So, I bought a battery blanket and a block heater… That car was totaled with a deer 3 weeks ago… Now I have this Buick without either heater… Both are on the way and will install them tomorrow. Just looking for ideas as to how to plug the battery pad in. Have thought of building a fire under it Up here heaters are a necessity.
You said it wouldn’t REMOTE start…does it start with the key?
I’m familiar with the conditions. We would have at least a week of -25F at night with highs below zero during the day. You can take two routes- heat the battery to improve the energy available or heat the motor to make it easier to crank. Considering the battery is inside the cabin, it might be easier to make sure you have a good battery and then get an engine block heater which will be easier to access on a frequent basis. If you’re stuck on the battery heater, why not just put some additional protective jacket over the cord and then route it to the lowest point in the door by the latch side and gently close the door on the cable. No need to make holes…
i love my garage.our company had an addition built and the contractor brought in a bunch of folks from iowa to do the mechanicals. i got to know several and they really complained about our cold mn winters.
I am not a fan of unattended battery heaters when the battery is not in the engine compartment and therefore behind a firewall. One short in the extension cord or the battery heater and you’ve just set your car on fire.
I recommend you get a good battery.
I am also here in MN. It is cold but your car should start. -12F this morning. I think you are focusing on the symptoms instead of the problem. You may just be out thinking all of the good advice.
But keep in mind the hundreds of cars around you that start and run without all of your precautions. Blanket can help, block heater will certainly help, but your car should start without either.
So consider addressing the other issues. Your shouldn’t rely on your remote starter in this condition, you haven’t used your key to turn the motor over. I bet if you got out and just cranked on it with your key, it’ll actually start.
Days of fuel injection has improved starts all over the world.
Perhaps something like this would help, at least for those extreme times when all else has failed.
Do you have a block heater? That worked for me to -45, never got colder than that. I would suggest that as the preferred option. The battery blanket won’t hurt either, I suppose the cracked window otion would be the safest.
In ND I used to use a lower radiator hose heater. It worked great. Block heaters are great too.
The challenge is always where to plug them in. On base, we just ran extension cords out to them. In town (Grand Forks), apartments had assigned spaces with posts outside with electrical sockets, the sockets being controlled by a switch in the apartment.
Yes in Grand Forks, the second time I moved there our apartment complex had outlets for the parking spaces, on all the time. First time in Grand Forks at GFAFB, living in on base officers quarters I do not recall if there were outlets or not but being Mission Essential personnel I was walking to my job.