anyone else have a problem with their alternator like... catching fire? I can't figure it out, there's no obvious wiring issue but my positive wire between the fuse and the alternator will become hot... like real hot. then the alternator usually craps out "switching current". Also I've got like a high 13v constantly. my blinkers/brakes/dash will go out from time to time, and then fix itself.
Alternator wiring problem
- Thread starter madseacow
- Start date
What's your basis for the conclusion that there is no wiring issue? Have you tested for shorts?
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/
no, don't know how.. and I'm not sure what the schematics mean or what to do them, I wouldn't mind learning but I don't know where to start. I see no obvious wiring issue meaning I see the black wire connecting to the alt fuse is getting hot yet I see no break in the wire. By picture I meant a picture of the picture of the fuse locations in otherwords I've misplaced the one that came with the car.
It sounds like somewhere, downstream of the alternator, something's drawing too much current or the wire is hosed. I'd start with a multimeter and test the wiring from one end to the other for resistance. With the car off and the battery disconnected.
EDIT: As for reading schematics, the TEWD isn't so much a collection of schematics. Primarily it's a wiring diagram/troubleshooting guide. As such it's a bit easier for some to read and understand. Start reading the Introduction, it has alot of the basics covered: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=002
EDIT: As for reading schematics, the TEWD isn't so much a collection of schematics. Primarily it's a wiring diagram/troubleshooting guide. As such it's a bit easier for some to read and understand. Start reading the Introduction, it has alot of the basics covered: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=002
What I don't get is what wire runs from the alternator to a fuse? Are you referring to the fuse box? Can you post a picture and tell us specifically which wire you're referring to?
Yea, I don't know how to use a multimeter
This is where I was seeing it get hot, followed it to the fuse box and took that apart. I found that in there the bolts I used to connect the wire were touching each other and were melting the surrounding plastic. I mounted it remotely since the original location was well... compromised.
The pink fuse is the new one, the 2 white wires seem to be getting hotter than the black. How do I start snooping with a multimeter?
This is where I was seeing it get hot, followed it to the fuse box and took that apart. I found that in there the bolts I used to connect the wire were touching each other and were melting the surrounding plastic. I mounted it remotely since the original location was well... compromised.
The pink fuse is the new one, the 2 white wires seem to be getting hotter than the black. How do I start snooping with a multimeter?
how do I find a voltage drop? is that a negative number? I don't get it. I've got a multimeter now but I don't know where to look, between the battery posts I've got 11 when it's off and 14 after it's been started, I've got a negative number between the 2 posts of the pink fuse in the pictures.. can you please be a little more clear on what I should DO
http://en.wikipedia.org/wiki/Voltage_drop
Put simply, you test the power with the multimeter's - lead on the battery's - terminal and the + lead on the + terminal. Then you move outward testing the voltage at each junction block (their 12v lines) while keeping the - lead grounded (on the battery's - terminal will do) until you hit a spot where the reported voltage is much less than you measured everywhere else. So, if you measure 14.1v at the battery and around 14v at most of the other locations but you read 10v at the taillight's 12v line the problem is in that line.
The problem could be in the grounding. Just reverse the testing methodology, keeping the multimeter's + lead on a known reliable 12v line or the + battery terminal and testing ground lines at the various junction blocks.
Junction Block and electrical connection locations:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=023
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=24
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=25
and so on...
If there are any electronics that aren't functioning correctly, start there. Use this page for testing procedures for each section.
Put simply, you test the power with the multimeter's - lead on the battery's - terminal and the + lead on the + terminal. Then you move outward testing the voltage at each junction block (their 12v lines) while keeping the - lead grounded (on the battery's - terminal will do) until you hit a spot where the reported voltage is much less than you measured everywhere else. So, if you measure 14.1v at the battery and around 14v at most of the other locations but you read 10v at the taillight's 12v line the problem is in that line.
The problem could be in the grounding. Just reverse the testing methodology, keeping the multimeter's + lead on a known reliable 12v line or the + battery terminal and testing ground lines at the various junction blocks.
Junction Block and electrical connection locations:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=023
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=24
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=25
and so on...
If there are any electronics that aren't functioning correctly, start there. Use this page for testing procedures for each section.
I was hoping he'd take that silver spoon out of his mouth and research it himself but no harm done I guess.
I was actually referring to measuring drop the other way using current. Involves putting the meter across either end of the same conductor or device while it's loaded. Any resistance in the path will be shown as a voltage. More accurate than open circuit testing. The method also works for grounding. He ought to check for ripple next time he's across the battery too.
I was actually referring to measuring drop the other way using current. Involves putting the meter across either end of the same conductor or device while it's loaded. Any resistance in the path will be shown as a voltage. More accurate than open circuit testing. The method also works for grounding. He ought to check for ripple next time he's across the battery too.
Okay, sorry, that's what he was doing. Either way he doesn't know what the values mean and we still can't help him unless he posts the specific readings. I'd still like to know the value he got when the tested the drop at that fusible link. What's that link rated for anyway?
yea, I'm sorry for playing the helpless routine. I researched it but my lack of knowledge on the subject just made the definition overwhelming. So I decided to just checkbook it, result: the plug on the back of the alternator was "bad". cost :175$, much obliged cre and jetjock; some people just can't be helped I guess