Turn signals and emergency flasher not working and will not start

Hi,

Does the left front signal turn on or do anything? I'm asking because the power supply to the left rear signal is provided by the body control module. So, to start I need you to check for power to the yellow wire on the left rear signal bulb.

I attached two pics. The first is the body control module showing how power is distributed. The second is at the light itself (rear) showing the yellow wire I'm referring to.

Do this and let me know what you find.

Joe

Hi,

If you are sure the bulbs are good, chances are it is either the switch or the logic module in the body control module. Ugh! I miss the old days. LOL

Listen, here is what I suggest to save us from replacing parts that are good. What really needs done is to have the computer scanned for what are called (B) codes. That will scan the body control module and see if it is the switch or the module itself. I hate to ask you to do that, but like I mentioned, I don't want to replace good parts.

If you could have that done, let me know what codes are found.

Let me know.
Joe

Hi,

Chances are AutoZone won't have a scan tool that can read body control module codes. You could ask or at least let them try.

Let me know if you have other questions.

Joe

Hi,

Okay, the most common cause of what you described is a loose or corroded battery terminal and is really easy to fix. Take a look through this link:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

If that isn't helpful, then do this. Keeping in mind the battery or the alternator can be failing, we need to check one thing at a time. What I want you to do is when the car is running, take it to a parts store and ask them to load test the battery. That way we will know if the battery is just weak. In most cases, they will do it free of charge hoping to sell you a battery.

If you can't take it, here is a link that explains how to load test one at home:

https://www.2carpros.com/articles/car-battery-load-test

Next, if the battery passes, either have them test the alternator at the same time or you can do it yourself. All you need is a multi meter or volt meter. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

When you check the alternator output, with the engine off, battery voltage should be around 12v. With the engine running, it should be near 14v on the meter.

If everything checks good, we will need to check for a voltage draw, but I'm not going to overwhelm you with that at this point.

Do this and let me know what you find. If possible, let me know the voltages you find if you do it yourself.

I will watch for your reply.

Take care,
Joe

Hi,

If the battery is good and you get one click, it is either the starter itself or a weak connection. Keep in mind, the starter places the heaviest load on the electrical system in the car. If there is a weak, loose, or corroded connection, usually you will get one click and then connection is temporarily lost. Since it starts right up when you jump start it, the first thing I would check are the terminals on the battery. Make sure there is nothing loose or corroded. I say that because when you attach jumper cables, the clamp on the cable can be allowing the terminal to tighten on the battery post and make the connection.

Please feel free to let me know if you have other questions. Also, I don't feel the starter is bad simply because it works properly when jump started. Even though there are two batteries, they still only supply 12v.

Let me know if I can help.

Joe

Sounds good. Let me know what is found.

Joe

Don't worry. We'll get it running. And like you, I miss the old cars. LOL They were much easier to work with.

Take care,
Joe

The turn signal flasher function is performed by the Body Control Module (BCM). That is why I'm thinking that is where the problem is. If you take a look at the attached picture, that is a portion of the body control module schematic for the signals/hazard.

Let me know what you find.

Joe

The IP stands for instrument panel. Chances are it isn't the cause. Plus, I assume it wasn't removed when this happened, correct?

Joe