Keep Blowing Fuse
11-21-2013, 02:17 PM
#1
Keep Blowing Fuse My dash lights, center console, HVAC, tail lights and rear marker lights will all stop working.
The fuse on the side of the dash keeps blowing only when the car is on. So like if the key is on and you turn the lights on, it won't blow but if the cars running, it will blow as soon as you turn the lights on.
If I put in a higher amp fuse it will not blow but I don't want to risk that.
Where do I start?
EDIT: Turns out there was a short on my driver side fog light connection, thanks
The fuse on the side of the dash keeps blowing only when the car is on. So like if the key is on and you turn the lights on, it won't blow but if the cars running, it will blow as soon as you turn the lights on.
If I put in a higher amp fuse it will not blow but I don't want to risk that.
Where do I start?
EDIT: Turns out there was a short on my driver side fog light connection, thanks
Last edited by xBrandonx; 05-31-2014 at 10:52 AM.
11-24-2013, 09:57 PM
#6
If you have fuses to spare, it might also be interesting to check and see if it happens in the ACC position without the engine running.
My first guess would be something on the circuit that is energized with the engine running (or with the key to the ACC position) like the HVAC. I'd try things with the system control to off and with the fans off and go from there.
My first guess would be something on the circuit that is energized with the engine running (or with the key to the ACC position) like the HVAC. I'd try things with the system control to off and with the fans off and go from there.
11-25-2013, 07:44 AM
#7
The problem is that there is nothing related to the TAIL LPS circuit which is powered when the engine is running but not when the ignition switch is in the run position with the engine not running (that's the situation I got from the original post).
That leads me to believe that something is borderline for failure and is only enough to blow a fuse when it gets the extra voltage from the alternator. With the ignition switch in the run position but the engine not running you will get battery voltage only - probably about 11 volts if the battery is in decent condition. With the engine running and a good alternator you'll get around 14 volts. Given that the resistance remains the same, the current (amps) increases with higher voltage... possibly just enough to blow the fuse.
If that's the case, it's going to be very difficult to find the cause. I would start by checking parking/running light sockets (especially front) for corrosion which might be causing abnormal resistance in the circuit.
That leads me to believe that something is borderline for failure and is only enough to blow a fuse when it gets the extra voltage from the alternator. With the ignition switch in the run position but the engine not running you will get battery voltage only - probably about 11 volts if the battery is in decent condition. With the engine running and a good alternator you'll get around 14 volts. Given that the resistance remains the same, the current (amps) increases with higher voltage... possibly just enough to blow the fuse.
If that's the case, it's going to be very difficult to find the cause. I would start by checking parking/running light sockets (especially front) for corrosion which might be causing abnormal resistance in the circuit.
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11-26-2013, 06:09 AM
#9
I think I was confused above and thought your HVAC fuse was also blowing but see that its your HVAC console lights as part of the equation.
Whitebird has a great point. I also wonder if there might be some odd "communication" between your tail lamps circuit and another circuit, which is hot with the car on.
Is your shifter light an aftermarket piece? It might be worthwhile tracing that thing first.
Is your shifter light an aftermarket piece? It might be worthwhile tracing that thing first.
11-26-2013, 07:33 AM
#10
I think I was confused above and thought your HVAC fuse was also blowing but see that its your HVAC console lights as part of the equation.
Whitebird has a great point. I also wonder if there might be some odd "communication" between your tail lamps circuit and another circuit, which is hot with the car on.
Is your shifter light an aftermarket piece? It might be worthwhile tracing that thing first.
Whitebird has a great point. I also wonder if there might be some odd "communication" between your tail lamps circuit and another circuit, which is hot with the car on.
Is your shifter light an aftermarket piece? It might be worthwhile tracing that thing first.
11-26-2013, 07:44 AM
#11
I would suggest removing the PRNDL bulb, checking for damage in the socket (e.g. loose bits of metal or bent contacts that might be shorting) and see if the problem goes away. It seems like quite the coincidence that the problem started when you replaced that bulb since it's on the circuit where you're having the problem.
11-30-2013, 10:49 AM
#13
TECH Fanatic
Pull the fuse. Measure voltage at each contact that the fuse contacts. At the 12v feed side you should measure 12v (with key on). On the other side, put the meter on ohms and measure continuity to ground. I bet you have a short to ground. That's the way that I troubleshoot short circuits and not have to keep replacing fuses while troubleshooting. As tsench said, you have a short not an open or high resistance. Do not go to a higher rated fuse ..... that's when wires melt and components fry if you are unlucky enough for the higher rated fuse to not open quick enough.
