WonkoTheSane

iTrader: (2)

A friend, it definitely wasn't me being a dumbass, nope, not at all, accidentally grounded the L terminal on my alternator. My terminals are just spade connectors since the original plug decided to buy the farm, and the insulation apparently cracked off of the L term spade.

I... errr... My friend accidently grounded it out while reinstalling the alternator last night, it made a little spark and now the IG1 doesn't seem to get power with the key.

Obviously, I checked the fuses already and I didn't find any blown (measured with a meter for continuity).

While I was probing around, I saw that the R term didn't have its' normal 12V on it like it should have, so I pulled it off the alternator and connected it to the battery and everything came up properly! I'm not sure if that's significant, but it leads me to believe that some sort of internal relay or gate is damaged in the alternator?

Can you guys think of anything additional to test/do? I haven't had a chance to run through the FSM checks on the alternator yet, but I figured I'd ask this while I'm at work.

Cheers!

HAILERS

What series car?

Does the starter work with the key to Start?

Voltage Seen on the L terminal on a series four comes thru the negative side of the alternator relay. When the alt is not turning, the Alternators circuit puts a ground on that W/B wire for the L terminal which pulls in the Alt relay who in turn puts a gnd on All the bulbs in the Warning Light unit so they come on to test all the lights in the Warning Unit if the key is just to ON and engine Off.......and of a alternator failure if the motor and alternator are tuning over.

Putting a gnd on the L wire or W/B wire of the alternator will have no negative effects on any fuse in the series four car.

Key On engine OFF..........the L terminal will show approx 3vdc if the W/B wire is connected to it. You backprobe the wire with it connected to the alternator to do this. The three volts represents the excitation voltage for the field of the alternator so it'll output voltage once it starts spinning up.

IF one shorts to gnd the B/W wire in the small plug............the ENGINE fuse will blow and the engine can't start............but starter will work 'cause it is not dependent on the engine fuse to work.

ON a series four if you pull the small plug off..........both wires should show batt voltage. If the W/B does not..........Meter fuse is blown..........if B/W does not have voltgage the Engine fuse is blown.

You probably have a series five and i just wasted my time.

satch

iTrader: (1)

You had the car battery hooked up when doing this.

WonkoTheSane

iTrader: (2)

Hailers - once again you come to the rescue.. Sorry, I should have said it was a S4, and the car was running when I... err, my friend shorted it.

The starter does work. The car will even start and run fine if you connect the B/W wire to some voltage. Of course it will stall as soon as your remove it.

I'll double check the ENGINE & METER fuses tonight. It may have shorted against the B/W, but I thought it was the W/B wire, but I have have it wrong.

I did see in the schematic that the W/B was supposed to be grounded, and if I just ground that the dash lights all come on still.

So, essentially, if you bypass the alternator all together (directly connect B/W to the battery and W/B to ground), the car runs normally, which is why I'm kinda leaning towards an alternator problem.

I'm still determined to buy you a drink one of these times I'm in FW area....

Thanks for the info!

satch

iTrader: (1)

I believe when you put some voltage on th B/W wire you are providing voltage in a "backwards" manner, which then supplies voltage back to the fuse box where the Engine fuse is located which then redirects the voltage to the Main Relay and Circuit Opening Relay thus allowing you to start the car so the Engine fuse is likely damaged goods.

If you can get the warning lights to turn on then the Meter fuse is okay.

WonkoTheSane

iTrader: (2)

Alright, I know this is a week old, but it was the first time I had a little bit of time to look at the car.

None of the fuses are blown, I checked each one out with a meter for continuity, but I did not have a chance to probe the L term or the R term to see what they were putting out. I'm hoping to get a chance to spend more time diagnosing it tomorrow.

satch

iTrader: (1)

If the Circuit Opening relay has voltage w/key to on in regards to the B/W wire located on top row middle position then that would prove the Engine fuse as being good. Also, the car doesn't need the alternator to start the car so maybe you could diagnose what is wrong with the car if it cannot start as separate from any issues with the alternator that you might have.

WonkoTheSane

iTrader: (2)

Welp, I feel like a damned fool.... It was a blown fuse. After reading your response, Satch, I went through with the meter and checked each fuse in the box for 12V, the 2nd fuse in on the 3rd row down didn't have it, but would still read continuity when it was plugged in? Either way, I pulled it and that one was blown.

Ouch! One strike against ego!

I'll check the alternator out tomorrow evening.

satch

iTrader: (1)

A continuity test only works on the fuse when it is individually pulled. When it is not pulled and tested in its respective slot the sides of the slot are still connected to each other and will therefor show continuity even if the center of the fuse is nonexistent and thus blown.

WonkoTheSane

iTrader: (2)

That makes perfect sense, I didn't think it through enough when I tested it last week..


Thanks for the help!

RX8ME

good luck!!!