Truck hard to start when cold, but real on, please

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Brake Controller Output

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rncordy

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My 2010 (see below) has performed almost flawlessly for over 5 years and 107,000 miles. But yesterday, with a temperature of about 45F, it balked at starting, but did. It didn't sound like a low/weak battery, just wouldn't crank and made weird clicking sounds, and the windshield wipers turned on! (I thought I had left them on from the rainy day before.) I then backed off the ignition switch and tried again and it cranked over and finally started. It ran fine, and restarted fine, the rest of the day. Except it continually showed on the Trailer Brake Controller a fault code of "CF" and showed the red icon for the trailer not being connected (and it wasn't).

Today, the same start up procedure occurred, with wipers coming on even though they were not turned on, with the added mystery of the radio failing to find any stations on Satelliite (and the HDD music would not play). WEIRD.

Do you think a low/weak battery could do this, or is it most likely a bad computer somewhere between the bumpers?

Thanks for your thoughts!

I'm leaving it on a trickle charger tonight to see if that changes things in the AM.

Bob
 
On all of my Ram trucks, 05,08, and the 2010, I had to replace the batteries at about 2 years old. I would get weird things going on, like the radio acting up, is a symptom of a weak battery.
 
On all of my Ram trucks, 05,08, and the 2010, I had to replace the batteries at about 2 years old. I would get weird things going on, like the radio acting up, is a symptom of a weak battery.

Thanks! Hopefully that's my problem, I'm 125 miles from a dealer or good mechanic! I've never replaced a battery on any of my 3 Dodge trucks, two having 5 years on the batteries and one with 7 years! Lucky I guess...

Bob
 
Modules on new trucks start getting really cranky with battery voltages below about 10.5v. It is interesting that some of the more obscure modules will set low voltage codes, but the important modules like the ECM are a little more tolerant to low voltage.
An inexpensive scanner will only report codes for the ECM, but I suspect if you had a dealer scan it there would be low voltage faults in multiple modules. Hang a volt meter on the battery and crank it to see what the voltage drops to. Bottom line is batteries are probably gone.
 
Modules on new trucks start getting really cranky with battery voltages below about 10.5v. It is interesting that some of the more obscure modules will set low voltage codes, but the important modules like the ECM are a little more tolerant to low voltage.
An inexpensive scanner will only report codes for the ECM, but I suspect if you had a dealer scan it there would be low voltage faults in multiple modules. Hang a volt meter on the battery and crank it to see what the voltage drops to. Bottom line is batteries are probably gone.

What voltage should it drop to or what voltage should it maintain when cranking when testing with voltmeter?

Thx!
 
What voltage should it drop to or what voltage should it maintain when cranking when testing with voltmeter?

Thx!

On a good quality battery cable with good connections and a good battery(s) 11 or so volts is about as low as it should go, Normally it will stay in the high 11's with two batteries and clean connections.
 
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