Truck cranks but won’t start after switching led light bar switch.

ANSWER : Hi there. Although we do not provide specific advice on mechanical issues due to aftermarket part accessory add-on’s, it is quite possible that the addition of the amp switch, it’s impacted the ignition system. I would start by verifying that your ground connection to the amp switch is solid and that it is installed in conjunction with Ford’s wiring specifics. You can contact a local dealer or search online to get a wiring diagram.

ANSWER : Hi and thanks for contacting Your Mechanic. If sometimes your vehicle will start with the new alternator and sometimes it won’t, then there is a loose connection in your charging system. Check all of the wires to the alternator and to the battery. Make sure that the battery cables are clean and tight. Make sure that the wires to the starter are clean and tight. A loose ground to the ignition system will cause the vehicle to not crank over. Check all of the ground wires from the battery to the starter. Make sure that they are clean and tight. If you need further assistance troubleshooting your no start situation, then seek out a technician, such as one from Your Mechanic, that can assist you.

ANSWER : Typically when the battery has been disconnected for an extended period and is replaced, an error code will be triggered in the ECU of the vehicle and disable the ignition system. This is done as a security feature; but tends to be a major inconvenience for car owners. The only way to resolve this issue is to have a professional mechanic complete a check engine light inspection, so they can download the stored error code, clear the code and verify that the car will start. If this is not the problem, a more in-depth inspection will need to happen.

ANSWER : Hi there. This does sound like an issue with the wiring. If the check engine light is coming on every now and then this means that when it does not come on there is no power to the computer. This can be the wiring harness issue or an ignition switch problem. I would have to test for voltage to the computer when the problem is occurring to be able to find where the issue lies. If you need assistance, a certified YourMechanic technician can be dispatched to your location to inspect your vehicle’s non-start issue and suggest any necessary repairs.

ANSWER : Hi there:

If you checked the oil and determined that there was no oil in the car, it’s quite possible that some internal engine components have seized up; which means there might be serious engine damage internally. Before you attempt to crank it again, please contact a professional mobile mechanic to complete a car is hard to start inspection; so they can pinpoint what is the source of your issues before it causes more damage.

ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.

ANSWER : Hi, thanks for writing in. I’d be happy to provide my insight. There are a variety of potential issues that may have caused this. The oil light coming on should not have anything to do with the truck stalling unless the oil level is severely low and the truck’s computer may have gone into "safe mode", which is a safety feature of the truck that is engaged when something goes wrong with the truck that may be catastrophic in terms of engine failure or safety. When this happens, the computer simply shuts the truck down and will not allow it to move in an effort to preserve the engine and safety of the passengers.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this no-start issue for you, and make or suggest any repairs as needed.

ANSWER : Hi there. There could be two problems here. It is possible that your battery is bad and will not take a charge from your alternator while driving. In that case every time you shut your car off you will not have enough juice to start it again. Inspect your battery – it should have at least 12.5 to 13 volts to start your car, if it doesn’t you will need to replace the battery. The second problem could be that your alternator is bad and not charging your battery, in this case you will need to replace your alternator. Both the battery and the alternator can be tested in your car. If you would like to have the car checked for you, a certified professional from YourMechanic can come to your car’s location to diagnose the starting problem and proceed with repairs.