Today: things to check when your ride won't start in the cold.

Dear Car Talk

Dear Car Talk | Mar 01, 2011

Dear Tom and Ray:

I have a 1993 Dodge Ram Charger that is currently in the shop, where it spends most of its time. Since it's big, has four-wheel drive and is set up for a plow, we figured it would be a good winter truck. The problem is that as soon as the temperature drops below 40 or 50 degrees, it won't start. We've done all the usual -- wires, plugs, cap, rotor, etc. Even the mechanic can't figure it out, because it seems to be electrical. It doesn't get a spark in the cold, yet it starts fine in warm weather. Any ideas?

-- Billie

RAY: I would say that's a serious flaw in a winter truck: not starting in cold weather.

TOM: It could be a number of things, but if I had to guess, I'd try replacing the crank angle sensor.

RAY: The crank angle sensor is a magnetic coil that reads little grooves on the crankshaft and tells the computer when the crankshaft is turning, and how fast. If it's not working -- it can fail in cold weather -- the computer doesn't know that the crankshaft is turning, so it doesn't send spark to the spark plugs.

TOM: It's actually easy to replace -- it screws right into the block. So ask your mechanic to give it a try.

RAY: If that doesn't fix it, maybe it'll become your summer vehicle, and you can use it to plow the fields instead of the roads.

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