Jumping between the Left(ground) and the cigarette lighter ground returns function to the map light. I show 6v between the terminals, but 12v between the Rt terminal(supposed to be 12v) and the cigarette lighter ground.
Sitting in the driver seat, the Rt wire in the connector behind the mirror is 12v while the left appears to be ground. If that fuse is blown, none of those things work.
I can confirm the rear view mirror lights are fed 12v from the 15a fuse under the hood that also feeds the daytime running lamps, dome lights, and radio. I heard a pop and smelled the lovely electrical smell. I was putting a new LED bulb in my maplight on the rear view mirror and managed to short between the 2 terminals. I wouldn't think the OEM mirror does, but since you don't have a meter, are you sure you had the wire polarity correct when you hooked the mirror up tthe cut wires?ĭigging a thread up from the dead. You can pop off the A pillar trim and run thenew wire up behind it, then just tuck the wires under the front of the headliner.Not knowing the internals of the old or new mirror, I would guess that the new mirror cares about polarity. If the wires are goo, and the vitages are not coming out of the fuse block, it would be troubleshooting the fuse block or replacing it would be a huge task, at that point it would be a lot easier to just insulate the cut ends of the wires and run a new pair of wires from some other fused 12V and ground for the mirror.
Without knowinig which of the wires is not providing the voltage it is supposed to, it's hard to know what to look at next.Since it's somebody else's car, you may want to trace back and fix the real cause of the problem. You could check for 12V on pin 3 and for a ground on pin 1, and if you had a meter you could check the wire itself for continuity. The 12V side goes to a connector on top of the underdash fuse block, there's a pic of that connector in. Do the cut wires provide both 12V and ground? If not, which one is not what it is supposed to be?Assuming that you are able to determine which of the cut wires is not what it is supposed to be, then you'll need to trace them back to some other point and recheck them there. Have you reconnected the original mirror and verified that it no longer works, and connected the new mirror and it too does not work? Have you have hooked both mirrors up to some other 12V source and verified that the mrrors are good?a multimeter would help, or make a test light like GMJAP said. The initial mirror was the one that had the map lights in it, and you cut those wires to reuse for the new mirror. (So I don't think you'll find any other symptoms.)There is not, as far as I know, any how-to on replacing it here. I think it says "Toyota" in big molded letters on it.It's unlikely that the whole thing is blown, just the transistor or whatever device provides the switchable ground for the map lights.
is there a how to on replacing it?The MFAM is a white or greenish box on the underside of the dash fuseblock. If the bulb then doesn't light across the map light wires, you know there's a problem with ground.Did you cut both wires at the same time? This could have effectively shorted 12v and ground, allowing a lot more current than the resistive bulb would, which would blow a transistor or other silicon switch before the fuse would go.Quote, originally posted by jeffgtx »where is the MFAM? what else could not work if its blown?i have to leave tonight, so i might just have to bite the bullet and buy one and send it to him. Quote, originally posted by jeffgtx »i dont have a voltmeter, is there another way?Just use a 12v bulb & some wire (all easily available at Radio Shack) - if it lights up between the map light supply wire and the lighter socket gnd, you know the map lamps have got 12v.