Ok, so I just learned that my block heater connection has a sensor that prevents operation above -18 Deg. Celsius. That'* great, if all things were equal. However, with my aging vehicle, (remember the title says this is a 2006), I am experiencing hard starts at -12 Deg. Celsius. What can I do to assist starts if I can't operate my block heater? A new Interstate battery was installed about 1 year ago. Everything else electrical is original, as far as I know. I bought this van used, and it was two years old when purchased.

On one occasion, when I experienced a failed start, (the notorious clicking of the solenoid and fluttering gauges), I grabbed my battery charger with the engine start feature, and connected it for a few minutes. I came back, took it off, and attempted to start the van. Of course, it worked no problem.

I'm guess either my starter is going, or maybe even my alternator/regulator is experiencing some sort of failure. Either way, after plugging in my van every night, I never had much trouble starting it. Maybe I got lucky, or maybe the thermostat in the block heater cord is allowing operation above -18 Deg. Celsius. All I know, is I need to find out what'* going wrong with the van.

Any suggestions?

It sounds to me like you battery is struggling in the cold.
With your 1 yr old interstate, how many CCA is listed on it? 800CCA ? Have a shop load test it and when it'* running, check the voltage amp outputs as well, if possible. Many shops can do this for free.
Where are you located, you are mentioning Celsius....are you in Canada?
Keep in mind that at -18c you only have 40 % of CCA available and the vehicle requires a heck of a lot more energy to start it at those temps.

A block heater will make it a whole lot easier to start and using a True Full Synthetic engine oil will also help greatly. The block heater should work when it is plugged in. IDK about this-18c limitation.
You could also consider a battery wrap, or battery blanket, plugged in overnight.
I trickle charge my batteries up in the cold weather, and also use the best battery an Osyssey AGM.
These types (AGM) can produce a whole lot more power over conventional lead acid batteries in cold weather initially, which is what you want.

Thanks SoftRide for the information. The battery is an Interstate Megatron II, CCA 700. It should have plenty of power for this weather. The OEM battery was only 600 CCA. It was replaced because of several mornings I'd come out and found it dead, even in the summer. My mechanic determined it had a soft cell.

I have considered a battery blanket, but I thought the block heater would have been sufficient, as it has been in the past. However, technology has changed, and gone are the days of just simply plugging in the block heater.

Yes, I am in Canada, and our climate is similar to Buffalo or even Detroit.

Do you have a battery charger, try plugging that in overnight and go get your battery load tested. Keeping a trickle charge on it over night should "eliminate" your starting headaches.
Talking about "Eliminator" here is a "cool" battery that wont let ya down..

I have seen that truck and I think it'* hilarious. Personally I'd love to drive it at least once!

I do have a trickle charger and I'll give that a try tonight and see how it is tomorrow. If that works,I can dig up a quick connect so I won't have to raise and lower the good all the time.

Look forward to hear how she does in the AM then.
Do you have a battery tester/hydrometer? You open the water caps up, suck up the electrolyte, and it will give the current specific gravity or state of charge on each cell.
These are handy to have, and you can tell right away, how much charge you have in there. A weak cell shows itself quickly.
I have a c-tek automatic charger that are really good quality.
Comes with disconnects too. and small, fits so nice under the hood.
Just remember, don't drive off with stuff plugged in! (ask me how I know) LOL
CTEK® 4.3A Smart Battery Charger | Princess Auto

LOL! Ok buddy, ill let you know. I just connected my trickle charger. Lets see what happens!

i replaced my batteries with interstates they last a long time. i never had to plug it in at night or charge it over night if it gets driven. if it doesnt get driven or its just short trips thats a different story. the little 3.4 doesnt require much that much battery should crank her for a good long while. sometimes the electrical connections start getting corroded and will have the same affect or if the alt connections are corroded it wont charge the battery properly. if it sound fine but doesnt start could be a fuel problem, old fuel pumps like to go out in the cold, as they draw more and more power the older they get.

Well it wasn't a great test as the temperature didn't go below -3 Deg. Celsius last night. However,I noticed that the battery voltage as indicated on the information center was reading 13.8 when I first started the van, and got up to 14.1 by the time I got to work. Usually it hovers close to the 15.2 Mark

not supposed to be that high, should be 14-14.5 when you first start it then go down as the battery charges to 13'*.

i would check at the battery with a meter and see if its right