So I've been having this problem where my car would start at times and then not start at other times. Battery is good at 12 volts. Thought it was the ignition switch but turns out otherwise.

on my voltage gauge, when the car is on accessory, it reads 12 volts but when turned to ON, I get zero voltage.

Here's the weird part, when I turn the key to ON, I get this clicking noise under the hood. Followed it to a horn relay.

Now my question, would a bad relay such as the horn relay cause the car to not start at all? I'm going to order one anyways an replace it but I find it weird that this could be the problem.

 

No there is no chance. Clicking from electrical components tends to happen during low voltage situations. Give us more info about when you try to start the car. So you are saying this is a no crank no start? Where are you doing this voltage check? If the car doesn't crank you should be checking the voltages at the starter. Even just a test light is fine to check with at the starter. If you can confirm no crank signal is going to the starter than now you have it narrowed down instead of jumping all around.

 

Just tested the battery and thats fine...12.8 volts. When the door is shut and the keys out, the alarm led blinks normally. But once the key is in the ignition, it goes crazy, blinking very rapidly. Then when i turn the key to accessory, i get no light at all, nothing on the dash. If the door is open when i do that, i get a very faint light on the "open door" light. When i turn the key to ON, its like there's no battery at all.....all dead.

I hooked up another battery, as if to jump the car, same thing....all dead. Would a bad alarm system affect the car like that. Im thinking about taking the alarm out completely to see if thats that cause

Regarding the cranking, there's no electricity to even send to the starter. Its as if there's no battery installed at all.

Completely lost at this moment.

 

I would remove that alarm for sure if it was your or atleast disable it and test the car with it all unhooked and hook it back up after if you find a different cause. Certainly sounds like the alarm is killing off ignition voltage.

 

Yeah that would've been my first guess, that the starter is bad or the battery is bad. I would then take the starter to autozone and have them check it. If it checked out, i would then look at all the wiring to make sure nothing melted or got cut.

 

So after many days of not knowing what the heck is going on, i finally figured it out

It was not the ignition switch, starter, battery, relays, alarm or anything like it.....instead it was the terminals needing a deep cleaning. Yep, it was that simple. $4 for a can of battery cleaner and problem solved. I feel like a tool.

Thanks everyone for your input.