(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
There is no fuse in the circuit. With the key on, voltage comes thru the ignition switch to the bulb in the dash and onward to the alternator via the small brown wire that plugs into the alternator.
If the bulb does not light when the key is turned to ON, the alternator cannot charge.
Sometimes the bulb is bad, more often, it has just decided to quit making connection with the pc "board" behind the dash panel. Sometimes wiggling stuff around will make it start working again if the bulb was good and not burned out.
This is a common problem with these cars. Now, if the bulb cannot be convinced to light...there are a couple of potential fixes, or so.
First, however, I would unplug the the brown wire from the alternator and ground it to the engine...then turn the key on...if the light comes on, then you know you have an alternator problem, if it still does not come on, then you know you have a problem in the circuit...most commonly the bulb or its connection.
Okay, one cannot simply supply a voltage from an ignition switch source to the alternator as the bulb serves as a resistor to drop the voltage a bit. Leaving out this resistance will burn out the diodes in the alternator in short order.
One can take a 475 ohm resistor and insert it in a wire coming from the ignition switch and going to the alternator to replace the brown wire circuit.
One can buy a similar plug and play device from John Spina at Casper's...think it connects between the wastegate voltage feed wire and the alternator.
One can replace the 475 ohm resistor with a dash lite bulb and similarly run it from an ignition switch source...and it will come on and off just like the one in the dash did.
And, of course, one can mess with the one in the dash until it works....
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