2008 Chevy Malibu with 3.6 liter Noah buzzing noise coming from the ECM and no power going to the inside fuse box.

ANSWER : Hi there. Check the battery and see if there is power and a voltage of 12.6. If the battery is dead, then either charge the battery or replace the battery with a fully charged battery. If the battery is fully charged, then check all of the wires to the fuse box and make sure that they are all tight. Clean all ground wires to the frame and to the fuse box. If there is still no power, check the main fuse and see if its burned. If all of the fuses are good and there is no power, then the ECM (computer) needs replaced as the ground switch inside the computer is burned. If you need further assistance with troubleshooting your electrical system, then seek out a professional, such as one from Your Mechanic, to help you.

ANSWER : Hi there. Typically when this issue occurs, damage will be instant – meaning if it’s going to damage the ECU, replacing the fuses would not help start the vehicle. So, at first glance, I would assume the ECU is OK. What is more likely is that you have an exposed wire somewhere that is causing the fuses to pop. Trying to diagnose these issues can be tricky sometimes, so it might be a good idea to have a professional mechanic complete an electrical problems inspection to isolate why you’re having these issues and recommend the right repairs.

ANSWER : For this, Silicone spray is one tool I personally like to use especially on rubber or silicone seals. The spray will leave a water-tight film on the electrical component and offers a moisture resistant coating. If you would like to have this checked, an expert, like one from YourMechanic can come to your car’s location to inspect the electrical system in order to scope the problem out and pinpoint any problems.

ANSWER : There are quite a few reports of PCM (Powertrain Control Module, AKA computer) failures causing your problem, but before you go replacing the PCM, do some more pinpoint tests. This may require you to find a wiring diagram of all the wires coming from the PCM.

The first thing I would do is to connect a scanner to the car and see if you can communicate with the PCM. As a technician, I have access to communities of technicians where repeat failures are reported. In these reports, it is most common when the PCM fails in this fashion, that you will not have PCM communication. If you do have communication and the Check Engine Light turns on with the key on, I would be leaning away from the PCM being the problem.

However, this is by no means conclusive. You could be correct in your thoughts about a wiring problem mid vehicle. On most GM vehicles, there is a connector along the frame rail for the wiring harness that services the fuel module in the tank. This has problems with corrosion because it sits under the vehicle exposed to the elements. But why am I doubtful of this, and this will require you to confirm where the power starts and stops, is you stated you didn’t have power from the fuse box. This would be before this connector and the fuel pump. If this is the case, I wouldn’t be thinking of a wiring problem mid vehicle anymore.

I am wondering if you confirmed the fuse box was getting power? It is a very common problem that when we move wiring we inadvertently move the damaged wiring and fix the problem for the short term. You may have done this when replacing the fuse box. Not to mention you seem to have an intermittent failure on your hands. This compounds the process quite a bit.

I’m not sure how you are confirming you have power at the various points, but I highly recommend a test light over a multi-meter. A test light draws current and a multi-meter does not. There can be voltage present but not a good enough connection to carry current. This is a very important distinction when you are battling bad connections. The problem with a test light though, is knowing when it shouldn’t be used. Some test lights draw too much current and can damage computer modules. Even us technicians perform tests on modules at our own risk.

The best way to test a relay is to simply use a jumper wire to bypass them. If I suspect there is a problem with the power supply to the fuel pump, this is the first thing I do. This way I can be sure it isn’t the relay or the PCM that turns the relay on. If the fuel pump does not run, use the before mentioned test light to find where the power stops. This requires you to methodically track the wire back to the fuel pump. I usually start at the central connector, if it has one. Not all of them do. I go directly to the pump if I can, but this is often not easy to access without dropping the fuel tank down. If you successfully confirm power to the pump, it maybe a bad ground, in which case the easiest way to confirm this is to add a ground yourself.

If this circuit checks out good, a few other things to check are power and ground to the PCM. Locate the wire from the PCM that powers the fuel pump relay. This can be done at the relay connector while you are testing the fuel pump circuit without the relay. When you turn the key on, on of the four terminals should receive power from the PCM for a few seconds. It will turn off after a couple of seconds if the PCM doesn’t see a signal that the motor is running. This is normal operation.

As for the air pump, I wouldn’t think this is an indication of the problem unless this occurred at the exact same time as the fuel pump failure. If so, I would suspect a wiring harness is shorting to ground somewhere. If they didn’t occur at the same time, this is most likely a separate issue.

The challenge you have here is isolating each part of the system. The PCM, the fuel pump relay, or a wiring issue. The PCM is actually fairly easy to check. Is the Check Engine Light on with key on and does it communicate with a scanner? Then follow the fuel pump relay test I outlined above. If it is a bad connection somewhere in the system, you will need a good wiring diagram and a well thought out plan to isolate where the problem is. This can be the most difficult to diagnose, especially if the problem is intermittent. Find a wiring diagram and study it carefully. If you’d like help, you can have a qualified technician, such as one from YourMechanic, to inspect your car’s loss of power and make the correct repairs.

Good luck. I hope I have been of assistance.

ANSWER : Hi there. Remove the fuse to the reverse lighting system. On the side that does not have power, use a digit ohm meter and check for resistance. The meter should read OL (out of limits). Now, turn on the ignition key to the ’ON’ position, set the parking brake and chock the wheels, and put the transmission in reverse. Check the connection again for resistance. There should be a resistance of 5 ohms or less. If the meter reads OL, then there is a break in the wiring from the fuse box to the switch. Since you disturbed the fuse box, there could be a wire that is loose or broken that goes to the reverse lights. If you need further assistance with your reverse lights not working, then seek out a professional, such as one from Your Mechanic, to help you.

ANSWER : It is possible that your clutch has failed. The sound you are hearing is likely due to the clutch not engaging with the engine due to it being worn. I would recommened having your transmission inspected by a qualified transmission expert to determine if your clutch requires replacement in order to resolve this issue. This inspection may require removal and partial disassembly of the transmission in order to verify that the clutch has failed.

ANSWER : Hello and thank you for contacting YourMechanic. The book says that you can use a 15, 20, 25, or 30 amp fuse. The power to the heaters are operated through the wiring to the main harness. There could have been a wire tied into it to make the seat work on the same circuit as the driver seat. This is common to find in the vehicles.

You can try putting a 15 amp fuse in the slot and see if the seat works. Try to avoid using a high amp fuse for if there is a problem with the heater you don’t want to burn it. If nothing seems to work, then the heater in the seat has failed and needs replaced.

If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, that can assist you with a seat inspection at your home or office. Best of luck.

ANSWER : Hi there. If the screw is just spinning and not coming out, take a pry bar and put it under the fuse box and slightly apply a little pressure to the box and unscrew the screw. Then the screw should come out. If for some reason the screw will not come out, then you may have to use a drill and drill out the screw. If you need further assistance with your fuse box removal, then seek out a professional, such as one from Your Mechanic, to help you.