Electrical issues

[Devinj234]

I have a 15 ram 1500 and I've been having issues with it. I fixed my alternator issue but now when I turn on the truck I get "left turn signal out, parking light out, right brake light out, license plate lights out" and when I drive it the rear sensors do not work and my reverse camera doesn't work.

I have replaced and reprogrammed a new BCM and it still has the same issues. Makes me think there is an electrical module that controls the rear electronics???

can anyone help me out.

 

[RamDiver]

Welcome to Ram Forum, Devinj

Are there any other operational issues with the truck?

Did all of these faults appear together?

I would be checking ground blocks on the truck. You could also try to follow the ground wire from any of the inoperable lights if you have trouble locating the common grounds.

You might get a multimeter and test one of these failed lights socket for 12 volts when the light should be on and that would confirm the ground fault.

Test both the socket contacts for potential while using a good ground.

Also, how old is the battery and when were the posts and clamps last cleaned?
.

 

[Jeepwalker]

RamDriver has good advice. Look around the rear of the truck for major grounds to the frame and to the box. Make sure they're good, and the wire inside the insulator is good too. I know on my pickup there's a major ground near the filler tube by the rear wheel. But I'm pretty sure there's got to be a ground in the rear too.

And grounds from the batt to the engine and the body. It's a good place to start anyway.

 

[indept]

Welcome to the forum.
So what did you do to fix the alternator issues?

 

[Devinj234]

Welcome to Ram Forum, Devinj

Are there any other operational issues with the truck?

Did all of these faults appear together?

I would be checking ground blocks on the truck. You could also try to follow the ground wire from any of the inoperable lights if you have trouble locating the common grounds.

You might get a multimeter and test one of these failed lights socket for 12 volts when the light should be on and that would confirm the ground fault.

Test both the socket contacts for potential while using a good ground.

Also, how old is the battery and when were the posts and clamps last cleaned?
.

I have checked all connections and they look good. I sent back the bcm and got another one with the same part number but havent reprogrammed it because i figured its the same thing, when i swap them the same problems occur as well as new problems. Im so confused.

 

[Devinj234]

Welcome to the forum.
So what did you do to fix the alternator issues?

I was dumb, it was literally a fuse from the alternator to the battery but never noticed it because of the positive terminal cover, I thought my alternator was going bad but it wasnt, during that time I pulled the negative terminal off while the truck was on. i read that newer vehicles such as this one do not like that and can cause more issues. thus i fixed the fuse problem and all these other issues started to arise.

 

[RamDiver]

Our trucks have become rolling computers with a myriad of interconnected peripheral sensing devices. Fooling about with the main power supply (battery) while running can cause serious grief, as you have seen.

Troubleshooting and diagnostics of any electrical fault, simple or complex, always start with the basics.

How old is your battery and when was the last time both posts & terminals were cleaned?

Pick up one of these battery terminal cleaners and clean both the posts & clamps on the positive & negative sides of the battery. If it were my truck, I'd also use a thin coating of dielectric grease on both the posts & clamps.

There's not much point in trying to pursue an electrical fault without starting at the beginning.





If you don't own a digital multimeter and are unable to borrow one from a friend, you might look for something inexpensive to buy. You will always find uses for it in the future.

Regardless of the age of your battery, you will want to check the voltage after sitting overnight and at high idle, 1500 to 1800 rpm.

The float voltage (after sitting) should be about 12.5 to 12.8 VDC.
The voltage at high idle should be about 14.5 to 14.8 VDC.

If the battery is about 3 years old or more, visit an auto parts store and have it load tested. I strongly prefer an analogue toaster-style tester because it will never lie and the digital testers have been known to be wrong.

Toaster style battery tester below;


.

 

[Devinj234]

Our trucks have become rolling computers with a myriad of interconnected peripheral sensing devices. Fooling about with the main power supply (battery) while running can cause serious grief, as you have seen.

Troubleshooting and diagnostics of any electrical fault, simple or complex, always start with the basics.

How old is your battery and when was the last time both posts & terminals were cleaned?

Pick up one of these battery terminal cleaners and clean both the posts & clamps on the positive & negative sides of the battery. If it were my truck, I'd also use a thin coating of dielectric grease on both the posts & clamps.

There's not much point in trying to pursue an electrical fault without starting at the beginning.


View attachment 520577


If you don't own a digital multimeter and are unable to borrow one from a friend, you might look for something inexpensive to buy. You will always find uses for it in the future.

Regardless of the age of your battery, you will want to check the voltage after sitting overnight and at high idle, 1500 to 1800 rpm.

The float voltage (after sitting) should be about 12.5 to 12.8 VDC.
The voltage at high idle should be about 14.5 to 14.8 VDC.

If the battery is about 3 years old or more, visit an auto parts store and have it load tested. I strongly prefer an analogue toaster-style tester because it will never lie and the digital testers have been known to be wrong.

Toaster style battery tester below;

View attachment 520582
.

Unfortunately I have done all of the following. My last guess would be is that little wiring harness underneath the truck on the drivers side that connects the rear electrical components to the front, but I’m not sure what that’s called.

 

[RamDiver]

Unfortunately I have done all of the following. My last guess would be is that little wiring harness underneath the truck on the drivers side that connects the rear electrical components to the front, but I’m not sure what that’s called.

So, if you've verified all of the battery-related items in my previous post, I'd investigate common ground blocks next. The fault is most likely a common ground or you may have fried a module.

Do you have access to an OBDii reader to check for fault codes?

.

 

[Devinj234]

Yes I do, it’s giving me all issues that the truck is saying. Example, left turn signal out, fuel pump failure, fuel pump circuit high output. Etc.
the only thing I can think of since all of my problems are in the rear is this right here. I believe it connects all the electrical components to the rear of the vehicle.

 

[turkeybird56]

YUP, there is also a Similar hookup inside truck to the left of the brake pedal on the firewall to the right of the E brake. There should be 1 big clip. My 15 ED had one, my 2019 5th Gen has 3 clips. U can disconnect, check all pins, and re-connect, or just verify both clips inside and out are connected properly, not loose. Was a known problems on the ED's. If U pull the connections, U may want to disconnect battery 1st, verify and reconnect. SOMEBODY better than me needs to chime in here on this before U attempt, just in case.

 

[RamDiver]

Yes I do, it’s giving me all issues that the truck is saying. Example, left turn signal out, fuel pump failure, fuel pump circuit high output. Etc.
the only thing I can think of since all of my problems are in the rear is this right here. I believe it connects all the electrical components to the rear of the vehicle.

I'd agree with TB56, disconnect the battery and then disassemble and inspect both sides of that connector for water intrusion or oxidation on the terminals.

Before you explore that, I'd go back to the BCM, disconnect the battery, and remove, inspect, and re-install all connections on the BCM first, paying special attention to ground connections.

It's kind of mysterious that this flakey ground problem suddenly appeared after there was work performed on the BCM and the type of fault could be BCM related.

Those are my thoughts but someone with more BCM experience may have more info.

.

 

[turkeybird56]

I'd agree with TB56, disconnect the battery and then disassemble and inspect both sides of that connector for water intrusion or oxidation on the terminals.

Before you explore that, I'd go back to the BCM, disconnect the battery, and remove, inspect, and re-install all connections on the BCM first, paying special attention to ground connections.

It's kind of mysterious that this flakey ground problem suddenly appeared after there was work performed on the BCM and the type of fault could be BCM related.

Those are my thoughts but someone with more BCM experience may have more info.

.

They need to check both the Interior and Exterior connections.