Hi, welcome to 2CarPros. Lets see if we can figure out whats going on.
It sounds like you may have a bad ground issue.
I would start by ohms checking.....
The battery cable terminal to the cable, and the cable to the terminal where it bolts to the car to make sure the cable is good.
Then from the battery post to the engine, frame and body to make sure you have 000 ohms on all of them.
Also check the ground pigtail if the cable has one. This usually goes to the body.
I would suggest doing the same with the positive cable as well.
Here is a guide for testing with a meter if you are not familiar with one:
Let me know what you find out.
Saturday, September 7th, 2019 AT 1:40 AM