hellfire

Hey guys, I have recently replaced the brushes in my alternator, and it was working fine for about a month until yesterday I noticed my battery light would flicker when I hit bumps and stay on when on flat roads..

I popped the bonnet today and realised the terminal on the wires on the back of the alternator have melted off and there are a few signs of arcing...

Here's some pics.. Anyone know why it's done this?









Any input is appreciated

mick cassidy

this means you are pulling some serious load more than the wire can handle and it got hot
lights stereo ac heater??? do you know how to test your stuck with a sunpro gauge to see if there is a short or a drain on the battery then its shut down ? its a simple test by disconnecting the batt and hooking the test device between the pos batt terminal and the pos pos . cable and read the meters reading it will tell you your battery drain then you isolate the problem if there is one by removing each fuse one by one watching the reading then you know what CIRCUT is pulling the most load then you need to make sure its wired good and there are no hot wires hitting ground yup a paint in the arse !!!!

hellfire

Yeah it happened when I put the headlights on! I probably had the A/C and stereo running at the same time, but it's never done that before.. Is it possible that I installed the brushes incorrectly?

Thanks for your reply mick c

mick cassidy

well you have a problem there thats for sure . you see your accessories should not be pulling that much amps to heat up and melt that wire
do this get some 8 or 10 ga wire and get a good new connector and replace that section of burned toasted wire with say 6" or so of new wire make sure you SOLDER the old wire to new wire . run the stereo lights ac for like 3 or 4 mins shut it down see if that connector is hot ??
let it cool next do it with just the ac check again ?? then with the lights ???
i hope youre not running like 30 amp fuses in everything?? you see when there is excessive load a fuse will blow to protect the circut and not cause a fire
try to get that sun pro tester and it will help electrical problems require a lot of patience and ruling out whats not the problem maybe try to get a 110 amp alt in there ..well as far as those brushes go yes if there not touching the armature your alt is not making power or 50% power ....... take it to the local parts store most check them for free that could be it !!!

chriskatana

I had the same problem, the issue is not likely the load, it's resistance.
my problem was the stud and nut on my alternator were rusted, and the lug on the power wire was not making a good connection, this resistance causes arcing, creates heat, which melts the lug from your wire.. mine did it twice before I pulled the alternator, cleaned off the stud with a wire brush and replaced the nut. make sure when you replace the lug that you cut back enough wire to remove the damaged area of your wire.

hellfire

OK I got a reallllly solid battery connector lug to stick on to this beast.. Also got some 2.5mm electrical cables that are used on a house and a few new nuts..


I think Mick has hit the nail on the head in regard to the amps of the fuses I'm running.. I will have a better look, as the last thing I need right now is a burnt out Yota.

hellfire

Alright


I replaced all my fuses with the proper rating ie 20A, 15A, etc.. I replaced the line of cable until it was fresh with a new oversized battery lug on the end, I bolted that beast onto the alternator and it sparked upon connection as well as producing a click sound over near my fuse box area...

So I checked all my fuses and none are blown, I go to start the truck and nothing turns on except the battery light in the dash... I have lost power to the starter, radio, cigarette lighter, but my headlights, hazards, interior light all turn on... my battery voltage is fine and is only about 3 months old Any ideas.. I am over this truck I tell ya!

24Runna

Maybe a short somewhere? Thats what it sounds like.

myyota

Check the fusable link between the battery and fuse box, also check the main fuse, if either one are bad, you won`t get power to anything.

mick cassidy

ok rule #1 DONT GET FRUSTRATED electrical problems are like a virus in ur pc hiding there laughing at you someone some where sometime did something ..... modified this or that to create a short somewhere in the circut back to basics . you can remove the fuse to each circut and trace the problem this way like remove the fuse for the lights then test the ac system you really need to learn about ohms and resistance yes this may mean a class or reading a few books as i did but it makes you smarter to tackle the problem u got or can pay a electrical shop a few grand just to hunt this problem down
or you could order the oem harnesses from toyota for the area thats giving you the problem but its gonna be a dog replacing those circuits trust me i have a sunpro meter you gotta determine if you have a drain with all of the power turned off that is #1 please em me direct @ mickcassidy1@gmail.com i havnt figured out how to post pics here yet as i hav a hi res nikon and duh this site needs low res pics ... ok lets figure this out

wyoming9

iTrader: (1)

It appears that when you were replacing all these things you did not have the negative cable removed from the battery???

So you were in fact connecting your hot wire going to the B terminal of the Alternator . If there is any sort of drain on the system clock , radio memory, it will arc.

Did it arc on the stud , or did you touch this wire to the case ??

I would bet that it took out the fusible link.

I have also seen failures like this from not getting the connection tight for what ever reason .

As the fusible link protects the ignition switch that would account for your lack of power.

Might also be a good time to upgrade your ground cables.

hellfire

I had a section of severed cable touching on the alternator housing which was burning the fusible link every time I connected up...

I have patched the section of cable and all is working well.. Well atleast now I know my electrical harness back to front and it's all pulled apart, cleaned and shiny new electrical tape applied.

vital22re

iTrader: (2)

i'd say your alt is toast you may have overtightend the nut on the stud and the stud was grounding our your alt body or your wire terminal was grounding to the body of the alt. pull the alt and get it tested. imho, alt is toast and you're problems spread from that.