Toyota Celica Supra Forum banner

1 - 20 of 32 Posts

·
Registered
Joined
·
3,247 Posts
Discussion Starter #1
I got this info from Leslie, Jimvegas00, and Dave A. Well Jim told me but the info for this comes from Leslie and Dave A.

If you have a 82 or 83 and change out your alternator to anything newer. You will have a problem with your charge light and brake light not shuting off. I had this problem with my 83 7mgte car. so this why it wont shut off and how to fix it.

The 82 & 83 alternators (old style) have a different voltage regulator that is designed to work with the charge light relay. The 84 & up MKII alternators have a different design voltage regulator that doesn't require and isn't 100% compatible with the charge light relay. The charge light relay is actually more like a charge light control circuit that incorporates a PCB and a relay. On the 82 & 83, the charge light relay provides the ground path for the charge and brake lamp filaments. On the 84-86 MKII's, the voltage regulator provides the ground path. The reason for your charge and brake lamps staying On is because the later style voltage regulator in your new alternator (later style) isn't designed to work with the PCB electronics in the charge light relay and the relay is staying energized. A diode install will take care of this problem and will only set you back about 50 cents or less for the cost of the diode and 2 crimp-on spade terminals.

OK in the drivers side kick panel you will fined a Charge Light Relay. You may wont to take off the panel to remove the relay. When you do this you will see that the terminal looks like this
Blank--I-----EFI I
IGN --_-Gound-_
the (--) dont exist i used them to space it right
----I----I---
----_---_---
if you dont get it you will see when you take out the relay.
So what you need is to get a Rectifier Diode 1n4001 from radio shack. 50c for a pack of 2. Radio Shack part # 276-1101. Ok now you should cut most of each lead off then crimp or solder a spade terminal on each end of the diode. The annode end (labeled on the package) plugs into the IGN terminal and the cathode lead plugs into the BLANK terminal. Now start your car and check that the charge light goes out with your check engen light as soon as the car starts . Then release your e-brake to see your brake light also go out. If all works then your done.
Dave
 

·
Registered
Joined
·
1,643 Posts
Interestingly enough, I took an 84+ alt to a local rebuilder and asked for it to be rebuilt to 100 amp. I am using this in my 83 for my 6M. I have not done the charge light relay mod. I do not have this problem. I asked Leslie for the mod before I had it all in and then it never needed it. Then about 3 weeks into driving my car, the charge and brake lights come on. I'm like aw hell I'm gonna have to do it. Got home, shut off the ignition, turned it back on.....NO LIGHT! Still no light about a month later....

Weird.

Nick
 

·
Registered
Joined
·
788 Posts
By any chance, when the light came on were you at a stoplight and driving at night (or had a bunch of electrical things running)? The reason I ask is that when you rebuild an alternator for a higher current than stock, you usually end up with a lot lower current at idle. Ie., stock at idle may put out 10 amps, while a rewound alt. at idle will only put out 2 or 3 amps. This would most definitely cause the charge circuit to show that your alternator is not charging.
Just a thought, I could be wrong!!!
 

·
Registered
Joined
·
1,643 Posts
I had all my lights on and it came on at a stop but my car tends to idle a little high most of the time... Say about ~800-1K. My alt is putting out pretty close to a 100 amps at 800 rpm. NOTHING is dimed with everything on and hitting my brake lights. It drops to 12v when I'm stopped, everything on, foot on the brake and idle at 700.
 

·
Registered
Joined
·
3,331 Posts
awesome man, works great

i didnt do any soldering or crimping of blade connectors though, all i did was bend the leads well enough to fit in nice and snug, only tools needed are the ones to take the kick panel off to get to the relay (mines only held in by screws cause my cars missing 1/2 the screws just about hehe)

i just guessed that the relay is left out, and was correct. thanks again
 

·
Registered
Joined
·
3,331 Posts
got a pic of it uploaded, was taken with my camera phone as theres not enough room for my digicam

the end with the silver stripe goes towards the rear of the car, and the other end on the slot towards the front of the car. the pic is taken right side up so the diode goes in the bottom 2 slots
 

·
Registered
Joined
·
3,331 Posts
hrmmmmmm, did it according to diagram i thought, checked that the brake light worked, it did.
then i messed around under the hood for a bit, and now the car will not start. the injectors and coils arent getting power. the car is rigged big time wiring-wise(same as hwne i got it a couple weeks ago), so i may have broken something loose under the hood. we'll see, the guy that wired the car originally is on his way to help me out and see if i knocked something loose.
what would happen if i hooked the efi port the to ground anyways? as thats what i think ive done, looking at the diagram once again...... doh
 

·
Registered
Joined
·
3,331 Posts
guys im not seeing an edit button here, maybe its because im on netscape on this pooter. otherwise id be editing like crazy
DO NO HOOK THE DIODE UP LIKE THE PICTURE :)
it blows the efi fuse, i ran through all the fuses with my multimeter first of all of course but for some reason that one showed up as being ok just like the rest of em. been troubleshooting for awhile now thinkin fuses were good, went back and took em out this time to double check, sure enough the fuse was blown. :doh:

anyways, anode (the black side not the striped silver side) goes to the ignition terminal which is the top left one. the striped side goes to the top right terminal. i'll post another pic when im done for the night, again hehe. the car runs and starts with a new fuse and with the diode in place the charge light works great now too :D

thanks for the info Dave, it was my fault for doing it wrong haha. it works now though and thats what counts right?
 

·
Registered
Joined
·
667 Posts
dang.. I hooked it up just like the pic, blew a fuse, verified and tried again.. another fuse.. came here and saw the last post..

HEHE! :) I will wait til the new pic posts. Thanks
 

·
Registered
Joined
·
667 Posts
I dont see the EDIT button anymore. It was always there till now.

Anyways , It worked!! Thanks Gamble

Just follow the directions

"anode (the black side not the striped silver side) goes to the ignition terminal which is the top left one. the striped side goes to the top right terminal."
 

·
Registered
Joined
·
69 Posts
Thanks onedic :D . It works. I didn't realize the diode replaces the relay. I think the light now has no purpose, but at least it is off. May be used as an idiot light I suppose, if you wanted.
Gamble, Try the top two terminals, not the bottom.
Blank--I-----EFI I
IGN --_-Gound-_
the (--) dont exist i used them to space it right
----I----I---
----_---_---
rotate 90 degress clockwise and terminals look like in your pic.
----I----I---
----_---_---
 

·
Registered
Joined
·
69 Posts
your right mad 83 , the light should work
"anode (the black side not the striped silver side) goes to the ignition terminal which is the top left one. the striped side goes to the top right terminal."
I just realized I was repeating whats already been posted. I also forgot that it was posted that the light should still work properly. :dumbass: :oops: My light did stop working though (even before starting). must be something I did. My stock alternator had a square connector and the mkIII one has a round connector. I used spade connectors to wire my alternator individually.Before I saw this post I was afraid I hooked up some the wires wrong, or at least two may be switched. I still not sure if these even make a difference. I'll reposts if I fix it.
 

·
Registered
Joined
·
579 Posts
When the light is on after using a 84-86 alt in a 82-83, should the voltmeter read above 12V before the mod is done? OR does it act normal butjust that the charge light and brake light is on? Thanks/
 

·
Registered
Joined
·
9,840 Posts
God I love the search function .... 30 sec. fix,thanks guys.
 
1 - 20 of 32 Posts
Top