At the beginning I want to say i know almost nothing about cars - I am a computer technician.

My car - 2005 Civic DX 1.7L 70 000 miles on it. - never really had problems before

3 days ago i started my car, drove about .5 mile, suddenly heard noise (like some rock hit my car from the bottom) than i got the battery light on. Idecided that i have to go to my mechanic so i begun driving there and 5 miles later on a stop light my car started having rough idle and battery light turendoff, and check engine light turned on. My mechanic said that this could be because the alternator belt was kind ofloose, and than he fixed it by replacing a bolt or something(he didn't even charge me for it). Than he realized that my battery died and is bad (2,5 year old battery in arizonaweather could break easily) so i got a new battery.

After that the problem continues:

Every timeI start my carI have a battery light on, and rough idle. For the next one minute check engine light is comming on and off (during that time you can hear relay behind my glove box switching on and off). After a minute battery light turnes off, check engine light turns on. Engine doesn't have rough idle any more, but has no power and doesn't want togo to higher rpm's (i can drive it but up to 40-50 mph). AC doesn't work, engine termomether doesn't work, my mechanic's and autozone's check engine light reader cannot get connected to the computer. Exhaust stinks, and car likely burns a lot of fuel. My mechanic gave up on it, and told me to go to the dealership for diagnostics. My friend who works on cars told me it could be the car computer.

What do you think?

If it is computer is it hard to replace it? Where do i get it cheap?

Thanks a lot

 

Edited:

Avoid driving your car until it is repaired. Otherwise, you risk causing additional costly damage.

I believe you have several interrelated electrical problems:

1) The Check Engine Light [CEL]) is likely ON because the ECU is detecting a faulty signal from Electrical Load Detector (ELD) or its circuit.

2) The Battery Light is ON because the ECU is detecting a fault with the charging system, likely from the alternator or its circuit.

3) Problems (1) and (2) have caused voltage fluctuations in the system that have blown one or more fuses, including those controlling power to the scan tool connector, the A/C, and temperature gauge.
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A) I think a rock must have struck and damaged a wire serving both the alternator and ELD. You might find the problem wire yourself by raising the front of the car on jacks, crawling underneath, and inspecting the wire harness connecting the ELD to the alternator. This broken/damaged wire is your main problem.

B) Inspect all fuses in the under-dash and under-hood fuse/relay boxes and replace all that are blown.

C) No longer bring your car to the mechanic who replaced your battery. Find a mechanic more knowledgeable about Civics.

 

Thanks for that information

Itook the car to the dealership today and payd them $105 for diagnostics, they called me after 3 hours that they don't know what is going on and they cannot get connected to the computer either so they manually checked all the fuses etc and they cannot find out what is going on. They told me that i will have to pay another $105 for additional diagnosis on monday when they will be able to reach their "tech-line" for more electrical diagnostics.

I told them about what you suppose it could be and they said they will keep it in their mind.

Also whatI forgot to mention in my previous postI had my timing belt changed about a month ago (2500 miles ago) by my mechanic. Could the timing belt slip and cause all this trouble? Dealership said that getting to the timing belt will be their last resort but that it will be most time consuming so they will leave it for later.

Thanks for any additional information

 

I would argue with Honda about paying the diagnostics charge twice. It isn't your fault that they could not reach their tech line.

Please let us know how your car problem gets resolved.