How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Honda-Man Your Own Question
Honda-Man, Honda Mechanic
Category: Honda
Satisfied Customers: 3017
Experience:  I have an Associates Degree in Automotive. 10 Years experience on all makes and models. 20 Years Honda only including factory training. Over 30 years total.
Type Your Honda Question Here...
Honda-Man is online now
A new question is answered every 9 seconds

I had my mechanics replace the AC compressor on my 06 Honda

Customer Question

I had my mechanics replace the AC compressor on my 06 Honda Civic and now it won't start. It turns over but won't start and the RPM gauge doesn't move. He tried to put it on the computer but it won't let him into a lot of settings. For instance it has him locked out of the engine. Everything in the car has power and works except the radio.
JA: Many things can cause trouble with the A/C. Some simple, some complicated. Fortunately, the mechanic I'm going to connect you with knows all the tricks and shortcuts. Are you hoping to fix this yourself?
Customer: The problem isn't the AC. The problem is after replacing the compressor the car won't start
JA: Is there anything else important you think the Honda Mechanic should know about your Honda?
Customer: No
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Honda Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Honda
Expert:  Honda-Man replied 1 year ago.

My name is ***** ***** online handle is Honda-Man. I have over 31 years experience repairing Honda vehicles. Please remember to rate or accept my service while the Q&A is in progress or after we are done. Either way your question will remain open after the rating so you can get all of the advice you came for! If you are using the free trial, or have a subscription a rating is still required. It does not cost extra to accept or rate positive it's how the site knows when to compensate me.

After looking over the wiring diagrams it looks like fuse 20 amp #23(see diagram) in the under-hood fuse box has blown. Please rate or accept using the rating scale then reply after if needed. I am pretty confident the fuse has blown.

Thank you,


Customer: replied 1 year ago.
Ok. I will pass this along to my mechanic. What does this fuse go to?
Expert:  Honda-Man replied 1 year ago.

It goes to the immobilizer unit, data link connector, gauge control for the tachometer, and radio. Data link is where the scan tool connects. The immobilizer is what keeps it from starting. It's the only fuse I could find that would cause your problem.

Than you,


Customer: replied 1 year ago.
The mechanic stated they have checked all of the fuses and relays and they are all fine.
Expert:  Honda-Man replied 1 year ago.

About the only other thing I can think of is if they left the alternator loose. It needs to be removed or loosened to replace the compressor. If it's loose it can't properly ground so the alternator voltage spikes. This can fry the engine computer and cause issues with the tachometer. If the computer is bad they will be locked out too. Ask them to check the alternator bolts and also what lights are coming on. Like the green key light for the immobilizer or the check engine light?

Customer: replied 1 year ago.
far no luck. It goes into Honda tomorrow.
Expert:  Honda-Man replied 1 year ago.

Sorry I could not help more. If you would please let me know what ends up happening.



Customer: replied 1 year ago.
The Honda service tech(not the dealership I normally use) is trying to say it's the fuel pump. Which doesn't make sense and doesn't explain the other issues (no tach movement, no power to the radio). When I questioned him about the radio and tach he tried to tell me the car has to be running for the radio to have power and operate. And I know for a fact it doesn't. And it's a new battery so that's not the issue. Grrrrr so frustrating!
Expert:  Honda-Man replied 1 year ago.

I doubt the fuel pump failed. Really? the engine needs to run for the radio to work? The tach does need the engine running to operate normally but it still should move when the engine is cranking. I would ask them if they are able to communicate with the ECU. If the engine computer is not communicating it won't power up the fuel pump either. It controls the fuel pump relay. If it turns over the battery is OK. They need to focus on the ECU inputs, power, and grounds. If all that checks good you probably have a bad ECU. Your generation of Civic is known for issues related to loose alternator bolts like I mentioned before. ECU might not be the problem but I highly doubt it's a bad fuel pump.

Customer: replied 1 year ago.
My mechanic said he had checked the ECU, every fuse and connection he could think of before taking it to Honda. Honda cut and programmed my new keys and it didn't fix anything (surprise) so they are back on the fuel pump. Idk why this is so hard to figure out or why they are so stuck on it being the fuel pump.
Expert:  Honda-Man replied 1 year ago.

This so hard without actually working on the car myself. Tell them to go ahead with the fuel pump but if that does not fix it you won't pay. It's a reasonable request.

Customer: replied 1 year ago.
That's what my mechanic suggested as well.
Expert:  Honda-Man replied 1 year ago.

Either they will try harder to find the problem or you will get a new fuel pump for free. A qualified self respecting mechanic does not shoot from the hip. If they know what they are doing their diagnosis is guaranteed. Not "this is what needs to be done next", like throwing parts at it is a diagnostic method.