Could a new starter be causing my tail light fuses to blow?
How dangerous is it to replace a 10 amp fuse with a 15 amp?
Full story:
I had my starter replaced last week, and shortly afterwards I noticed that my tail lights were out. Turns out the fuse for the tail lights is blowing every time I start the car. My mechanic said the tail lights aren’t connected to the starter, so that shouldn’t be causing the problem, but I wanted a second opinion. He repaired the blown fuse by replacing the 10 amp fuse with a 15 amp. The lights now work, but I’m reading a lot online that says that’s dangerous, so now I’m a bit nervous. Any advice would be appreciated!
It is never a good idea to change fuses to a higher than specified rating. If fuses are blowing with proper fuses there is a problem that needs to be fixed.
A 10 amp circuit uses wires with diameters that can safely handle 10 amps without over heating and starting a car fire. If those wires are carrying more than 10 amps … well, you get the idea … not something you want to fool around with.
It’s possible of course the 10 amp fuses that were blowing out were all faulty. Vendors sometimes obtain a whole batch of faulty parts. I had a problem like this with light bulbs for a dome light. The only solution was was purchase the light bulb from a different vendor. You might try replacing the 15 amp with a 10 amp fuse obtained from a different vendor.
I can’t think of any reason why the starter would affect the tail lights. But such a thing might be possible, for example if the starter were faulty – shorted windings etc – and so it was drawing more current than it should. That could blow a fuse, and if that circuit was also involved with the tail lights, they wouldn’t work then either. Usually only the “start” signal to the starter is fused. That’s the signal that goes to 12 volts only when the key is in “start”. The main battery power to the starter uses so much current it can’t be fused.
Thanks for this; I just replaced the 15 I had in there with another 10 I got from the mechanic, and that seems to be working. It’s a 22 year old car, so possible some of those spare fuses were just really old and breaking too easily.
If it happens again, before replacing the fuse, check to see if the car will still crank after the tail-lights stop working. Would provide a clue.
Also make sure the tail-light ground is making good electrical contact with the chassis. An iffy ground back there can cause weird tail-light symptoms. I’ve had that problem myself on my Corolla. Look for a wire that goes from one or both of the tail-light fixtures to a chassis ground, in the trunk area.