During Bouts Of Cold Weather Or Often After A Hard Rain My Mercury Mystique Will Not Start. When I Turn The Key The Dash Lights Come On But The Car Does Not Even Attempt To Start. No Clicking Or Anything. However, After I Have Her Jumped Off Of Another Car She Starts Right Up And Continues To Run Without Fail Until The Next Hard Rain Or Cold Snap. I Have Had Both The Battery And Alternator Tested And Both Are Working At Full Capacity. I Don't Know What It Could Be. Please Help!!

How to Start a Car in Freezing Cold Winter Weather

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wikiHowFreezing cold weather can take a toll on car batteries. ... It's much more difficult to start a cold car with a mostly-empty tank, so do yourself a favor and gas up ...

Why is it so hard to start a car in the winter? - HowStuffWorks

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To start a car in winter, your engine has to work extra hard. Learn the top 3 reasons your car is hard to start in cold winter weather.

Debunking 5 Cold-Weather Car Myths - Popular Mechanics

One reason GM vehicles dont start, especially when the weather changes isdue tofaulty antitheft systems. Next time this happens, look for a light on the dash that says secury or antitheft. Picture might look like a car with a padlock thru the window, If you see any of these lights, that will explain why it doesnt start. This link explains. http://vatspasslockpasskeysecurityhelp.yolasite.com/

if lights on dash are going out its the battery need 12v plus to even turn car over has this been happening since cold weather as mine does the same but only in winter summer its fine

I WOULD HAVE BATTERY TESTED.BATTERYS ARE KNOWN TO DIE IN COLD WEATHER,ESPECIALLY IF THE BATTERY IS COUPLE OF YEARS OLD

Based on what you are saying I think the fuel pump would be suspect, these pumps stick and cause a no start in cold weather.
I am a 35 year Veteran Ford dealer technician

Check all of the fuses located in the black box under the hood close to the battery on top of the inner fender. All power to the car begins there. Check for large fuses 30 amp to 60 amp. Make sure the heater fan is left unplugged. When working on components under the dash always disconnect the ground cable from the battery

If it is happening more frequently in cold or damp weather it could be a spark issue. Wet or damp weather can effect spark plug wires if there is even minor damage to them (usually occurs durring rain). The other things that come to mind are the fuel pump and lastly the fuel line check ball that is in the fuel tank. If it is leaking then all the fuel in the line will drain back into the tank over night (pressure lost in the fuel line) and this will cause repeated, extended cranking when you first start the car in the morning or after the car has sat for several hours.

I i were you i would check the ignition. it sounds like you are only connecting some of the time. And yes it is very normal to hear the fuel pump kick on when you turn the key to the on position.

The on board computer does not show the error code using the MIL (check engine light ) In my case the fault is in the crankshaft sensor. Had to get the car to a shop to read the OBD1 port to find the error. Replaced the sensor and everything is good. Found out a fault in the cam sensor will cause the same strange issue with the cruise light.

If your gas lines were froze then there is obviously water in your fuel system which even once thawed could prevent your car from starting and may not run good if it does. With that being said it obviously has to be cold for your gas lines to freeze and cold weather is ******* your battery especially if it sits for a while. Turn on your headlights and see if they are working good as well as your dome light and radio. If they are not working good or at all charge the battery with a battery charger, even though you have tried to jump it. Your car will have a fairly small battery and the smaller the cold cranking amps your battery is rated for the worse it will be in cold weather, possibly even not turning your engine over. If you do all this and it does not work it may be your starter but my money is on the battery.