Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

A/C Fans Stop Blowing

So I have a phone changer in a cigarette/auxiliary plug in my 2007 Nissan Murano and when I go to plug in my phone to charge it while the A/C is running the fans they stop blowing. I have tried to locate any fuses/relays related to this but the few I have checked are fine. What could be causing this. Did I miss a relay/fuse? A bad phone changer?

There is no way the tiny drain for a charger would cause any problems in the electrical system, so my guess is that the phone charger is defective and causing a partial short in the system; possibly not enough to pop a fuse.

The obvious thing is to try another charger, they are pretty cheap.

This is the second post about a phone charger causing problems . The first thing to do it seems would be to get another charger and make sure it is a good one. Not something from the dollar store.

If there is a faulty ground related to the power outlet and the fan control relay coil I could see that as the cause of the trouble. Fixing the bad ground connection would fix the issue. The charger might also be adding noise to the power bus and that is causing a problem with the blower relay but I really don’t know how that could do that without seeing how the circuit is designed. Trying a different charger as suggested is a good idea to see it that cures the trouble. If it doesn’t then I would really suspect a bad ground OR, if the trouble is on the power side for the outlet, then check for a faulty power connection. This would be assuming that the outlet is connected to the same power lead as the fan control power is and the extra power needed by the charger is causing an excessive voltage drop on the power supply lead that is enough to kill the operation of fan relay coil. If the two things are tied to a common power source then I would really suspect that as the trouble. Checking the voltage across the power outlet while the trouble is happening will quickly show if that is the case or not. BillRussel kind of touched on this point but instead of being a near short problem, it is a high resistance or bad connection to power issue.

My guess would be a faulty relay. Most blower motor problems like this can be traced to a relay.

But it could be the charger or the 12 volt plug too, so I’d start there first.