That all should come back with up to a half hour of driving the car.............do yourself a favor and grab the terminal you removed and twist it by hand to check if tight, if it moves change it, these can seem to be tight and not be.................

 

Sounds like the battery terminals are either corroded, perhaps you didn't tighten the clamps good enough, or a combination of the two. If the terminals on the battery have a white/green crud on them then remove the terminal clamps and clean the terminals well with a wire brush or sand paper. Make sure the clamps are clean too. The idea is to get the best possible electrical connection you can. Then make sure the clamps are seated on the battery terminals as far as they can go and tighten them up good and proper. Even if they look clean it's no harm to sand them anyway for good measure as it appears one of the cables on the battery are giving you an intermittent connection. (clock/radio resetting)

 

Cleaning battery terminals on these can often make things worse, the OEM clamp is quite frankly garbage. It only closes down to so sized hole and any metal removal from post often makes it then loose where not before. Why the twist test............

 

Yup, the listed problems are not a result of disconnecting the battery.

They CAN be a result of poor connections at the battery, or nearby ground/wiring harness connections that could have been disturbed.

 

I agree. The terminal connection cranked down all the way, as far as it will go, is barely enough to be snug on the battery post. What's up with that?

 

I've always found that Windex (or some other methanol product) and a rag will clean off all that corrosion fairly easily. Wash your hands off afterwards, then apply grease evenly to the post before installing the terminal to prevent further corrosion. Following this application, the only time I have to remove my battery terminals is to replace the battery- or reset the car's electronics.

It is also helpful to remember that part of the reset procedure is to allow the vehicle to idle for at least 5 mins without touching the accelerator. This procedure should be completed while driving, but I've noticed in the past that sometimes it can take up to 2 weeks, and during that period the car will have incorrect- usually high- idle speeds. This time period depends on the drive cycle of the vehicle. If you routinely sit for long periods, then it will take less time, if you hop on the highway, and only stop for say refueling, it can take longer.

 

the battery connections are fine. It's just that disconnecting the battery messed up my car's computer. How do I fix that?

 

Like amc49 said, 30 minutes of driving should be plenty of time for the car's computer to reset itself. They're designed to do that.

If it doesn't, then you have other issues, likely in the cables themselves that were moved when you disconnected them.

 

The ONLY information from that internet article that fits YOUR car is that pulling the terminals of a RUNNING car can possible cause damages.

A little WRONG info. can lead you far astray.

 

A Walmart mechanic unhooked my car battery (while the car was running) to see if there was a problem with the alternator several months ago

 

Bad diagnostic trick to try, that hasn't been recommended since generators were in use on cars.

Many times folks are lucky & no problems result. If they do, they are typically major. Remember one here very well who needed to replace melted wiring & PCM, someone who had been lucky was arguing the point since he got away with it.

Either no problem or serious, don't see a middle ground when troubles result.

 

X2 to that, if alt has fired any diodes the a/c with battery removed can then short out the PCM or other things, the battery absorbs stray a/c current.

Only a dumb-ss drops the battery out of a system nowadays, whether at Walmart or Ford dealership. Every alt maker on the planet instantly voids warranty upon hearing that.

Test means nothing anyway as the alt can still run using residual magnetism even with no field current, or inconclusive test except to people who don't know what they are doing. And if you happen to have one of the alts that by way of regulator circuits then puts alt at the normal 75-100 volts any alt can make unregulated with no battery to load it, then things will get VERY interesting...........................

 

Update: I see corroded battery cables. One of them has crusty residue and bubbled tape around it (like it melted)

 

Fix it. The corrosion makes the wire overheat to then possibly start a fire. The earlier ones actually could catch fire.

 

Fixed. The wrapping around the wire looked burned and bubbly (like it melted) in addition to the corrosion.

 

After disconnect the battery, please check the battery terminals and then connect according them. You said that your electrical parts like clock and radio is needs resetting because of battery disconnect. That's of because all they getting power through battery.