alternator problems

[roadboy]

hey, recently after working on the ecu..my battery/tail light/handbrake light is on.
stupid me i forgot to disconnect the battery while depinning the 26 grey connector on the ecu side.
i have double checked that every pin iv disconnected it dosent run to the alternator wires ect.

first, when i turn on my car (ON, engine off) the three lights are on
i checked the wiring on the alternator side positive for ign+ and + feed) thats good.
but when i take off the plug, all lights disappear, iv checked all fuses its all fine
it can start (batt voltage is 12.2, when running its 11.7-11.9)
does that mean its the alternator? or could my battery not be charging and cause the light?
i know some will say just try with new alternator, but if it isnt then im stuck with a new alternator
btw- alternator is about a year old.
AVR tested last week alt was tested good
14.3 no load
14.4-14.5 with load

any advice? thanks

 

[tyang82]

try testing the alternator and battery again and the battery terminals.

 

[IndigoMKII]

Make sure the voltage regulator on the back side is still hooked up and in good shape.

 

[IBoughtASupra]

Have you checked the TSRM and used its steps? Check all terminals.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=CH&P=2

 

[roadboy]

yea, i checked all the steps, im going to replace the battery tonight, see if the lights are on, if it is, im just going to get a new alternator, thats what my mechanic said.

 

[roadboy]

soo, iv replaced my battery (tested good before i put it in), still has the three lights when ign is on and when car is started. replaced the alternator IC regulator, didnt start the car, but switched it to the on position.

is all the handbrake, rear tail light, battery light SUPPOSE to be on when the ign switch is only at the on position? i mean i dont even have my handbrake up, but when my handbrake is up, do it glows more brightly.
just asking some questions before i start it tomorrow or the day after.
thanks

 

[CyFi6]

Normal for all those lights to be on with key on engine off.

 

[roadboy]

even the handbrake light? hmm never knew. learn something new everyday..hope the lights go off when i start it!

 

[ForcedTorque]

Drive it by the auto parts store and have them put the tester on it.

 

[roadboy]

thing is, before i put a new alternator in, it would only be at 11.6. i put the alternator back in, but i wont be able to start the car till tomorrow night or in two days, just making sure its suppose to have the three lights on, especially the handbrake light, when ign is switched to on. i dont think itl last long driving it when its not charging

ok, i may have found the problem
on TSRM when you are looking at the pinout of connectors, are you looking at the FRONT of the connector or the BACK of the connector?
example:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=43
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=52

 

[CyFi6]

If you look at the diagram you will see that any time the charge light is commanded on, it will also cause the tail warning light and brake warning light to come on (part of the self test so you can ensure that those bulbs are working). Since with the ebrake down, the bulb is grounding through a diode, it gets a little brighter when you pull the ebrake up as it gets a direct ground source.

 

[jetjock]

It's them diodes at work...

 

[Nick M]

And when the battery light is on, it doesn't mean anything is defective or working normal. It means the battery is discharging. Now, if the car is running and the light is on....

 

[roadboy]

so heres another problem, replaced the IC regulator on the alternator and a new battery, just started it. all lights are staying on (battery, tail light and handbrake light) and its charging, but why isnt the light going off?

-Yes i tried checking continuity with the gauge,engine,ign FL AM1 fuses all are fine

also when i disconnect the plug off the alternator and just switch the ign to ON, the three lights wont be on.

 

[Nick M]

so heres another problem, replaced the IC regulator on the alternator and a new battery, just started it. all lights are staying on (battery, tail light and handbrake light) and its charging, but why isnt the light going off?

How do you know it is charging?

also when i disconnect the plug off the alternator and just switch the ign to ON, the three lights wont be on.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=042

You removed the ground for the bulb.

 

[bluebullet89]

Off topic but Road boy your car looks kinda purple in your avatar (I know it says maroon) any high res of the avatar pic? Gotta say in the avatar the purple doesn't look bad.

 

[roadboy]

I know its charging because I have a volt meter(apexi turbo timer) that shows the voltage of ign, shows 14.0 and that's with the battery fully charged.
I just have a question, on tsrm what way do you look at the Connectors, I say this because I may have switched wires with comb Meter wire and ign wire on the alternator side, but it was fine for the last year with no problems.

 

[SupraSean]

Engine off battery voltage should be 12.4 or higher. While running Your voltage should be somewhere in the 13.5-15v range Dc v. If you are getting 11v while running, that means the alt is not doing its job. If the alt tested good, then look to see what commands the voltage regulator to work.

 

[Nick M]

12.6v is battery voltage based on 2.1 volts per plate. Check open circuit voltage with a multimter, not a turbo timer. You can check it at the stud, and at the battery to see that there isn't any voltage drop.

I am not going to assume it is charging at 14v because your gauge said so. And that isn't insulting you, so don't get to wound up.

 

[jetjock]

Yeah some basic metrology, especially of the IG, S, and L terminals, is all that's needed.