Low voltage when turning on defroster
May 6, 2019, 03:57 PM
#1
Low voltage when turning on defroster
Hey everyone
So I'm having a weird issue where everytime I turn on my front defroster and sometimes my rear defroster, the voltage will drop to 12-12.4 volts.. I have a video if needed
Does this sound like an alternator going bad or something else?
I am also having an issue where I am running lean when coming to a stop and on startup.. there's a thread on here where someone had the same issue and fixed it by getting a new alternator.. not sure if these issues are related or not though..
So I'm having a weird issue where everytime I turn on my front defroster and sometimes my rear defroster, the voltage will drop to 12-12.4 volts.. I have a video if needed
Does this sound like an alternator going bad or something else?
I am also having an issue where I am running lean when coming to a stop and on startup.. there's a thread on here where someone had the same issue and fixed it by getting a new alternator.. not sure if these issues are related or not though..
May 6, 2019, 04:05 PM
#2
Hey everyone
So I'm having a weird issue where everytime I turn on my front defroster and sometimes my rear defroster, the voltage will drop to 12-12.4 volts.. I have a video if needed
Does this sound like an alternator going bad or something else?
I am also having an issue where I am running lean when coming to a stop and on startup.. there's a thread on here where someone had the same issue and fixed it by getting a new alternator.. not sure if these issues are related or not though..
So I'm having a weird issue where everytime I turn on my front defroster and sometimes my rear defroster, the voltage will drop to 12-12.4 volts.. I have a video if needed
Does this sound like an alternator going bad or something else?
I am also having an issue where I am running lean when coming to a stop and on startup.. there's a thread on here where someone had the same issue and fixed it by getting a new alternator.. not sure if these issues are related or not though..
You are not alone. My car does the same exact thing with the defrosters for front and rear. I am not sure why this happens for the front since it's just using the heater core inside the mix box, but the rear window heating element might draw a significant amount of current which causes a voltage drop that even affects the voltage at the fuel pump, REGARDLESS if you are hardwired to the battery. I have a voltage gauge directly wired to the fuel pump. Lower voltage at the fuel pump will cause a leaner condition.
Whenever I beat on the car, i turn off both defrosters. It's not even an initial current draw, it's constant. The moment I turn off the rear defroster, my fuel pump voltage (aka battery voltage) jumps back up to a steady 13.5v.
May 6, 2019, 04:08 PM
#3
Some good posts on evom today!
You are not alone. My car does the same exact thing with the defrosters for front and rear. I am not sure why this happens for the front since it's just using the heater core inside the mix box, but the rear window heating element might draw a significant amount of current which causes a voltage drop that even affects the voltage at the fuel pump, REGARDLESS if you are hardwired to the battery. I have a voltage gauge directly wired to the fuel pump. Lower voltage at the fuel pump will cause a leaner condition.
Whenever I beat on the car, i turn off both defrosters. It's not even an initial current drop, it's constant. The moment I turn off the rear defroster, my fuel pump voltage (aka battery voltage) jumps back up to a steady 13.5v.
You are not alone. My car does the same exact thing with the defrosters for front and rear. I am not sure why this happens for the front since it's just using the heater core inside the mix box, but the rear window heating element might draw a significant amount of current which causes a voltage drop that even affects the voltage at the fuel pump, REGARDLESS if you are hardwired to the battery. I have a voltage gauge directly wired to the fuel pump. Lower voltage at the fuel pump will cause a leaner condition.
Whenever I beat on the car, i turn off both defrosters. It's not even an initial current drop, it's constant. The moment I turn off the rear defroster, my fuel pump voltage (aka battery voltage) jumps back up to a steady 13.5v.
Yea even with the defrosters off, the car still stumbles when coming to a stop and on startup, which is making my tuner think it's a bad fuel pump.. too many problems 😂