Ok so I have replaced my voltage regulator and I still am having a constant charging light even though it is putting out 14.08volts at idle. Well here are some other things i have observed in my engine bay that may be a contributing factor. The ground wires are all screwed up one is running from the valve cover to a 10mm bolt holding a brake line on. The ground battery cable is running to the side of the head. Also there is an extra wire coming of the voltage regulator that goes no where and right next to that there is a yellow wire inline fuse holder that is completely empty. What fuse goes in there anyways? and where are the stock grounds supposed to run to?

 

BTW this is on a 1979 TE38 with a 2TC.

 

Thanks guys!

ok, if you fix all the engine earth points to the body correctly, that will only help the spark system and the starter motor opperate, the negetive battery line is supposed to be connected directly to the body!

 

just found a wiring diagram for a 1974 corolla, traced all wires coming from the alternator and regulator...

you should have a wire coming from the regulator to:

-battery (+)

-ground, earth (-)

-n and f (communication between alt and regulator)(two wires)

-(most probably your problem) dash warning light

-to the ignition switch (so when the keys are not inserted, the engine cannot be started)

 

so their is a separate wire that goes to the warning light, check where those wires are going to because you either have a short or the wire is connected to the wrong place :)

 

hope this helps and good luck :)

keep us posted!

The main earth going to the head is a good idea as it carries the current that the starter motor pulls, back to the battery. That load is far greater than any other circuit, so having fewer connections in the line is good. I ran mine onto the block when I moved the battery to the other side.

 

The body earth carries the lights and ancillaries.

 

You could take a multimeter and measure the resistance from the engine to the battery & from the body to the battery to check that connections are clean and tight.

 

Is the battery going flat?? Can you put an ammeter between the battery & its leads to see if there is a small current being drawn all the time?

Glad somebody understands the wiring diagrams better than me. I couldn't figure out the color codes, and the ground from body to engine can't be right, from the valve cover to a brake line strap on the firewall? As for it going flat I haven't checked it yet but I will tonight. That yellow wire with an inline fuse though is confusing me though. I can't figure it out for the life of me, even the wiring diagram says in line fuse but gives no rating for amperage.

the ground from body to engine can't be right, from the valve cover to a brake line strap on the firewall?

 

That doesn't sound like the starter return!! There should be a strap from the motor to the body or battery that is the same thickness as the battery +ve to the starter. That is the one that carries all the current.

 

Anyway, I feel your problem doesn't lie there... If your new voltage regulator is wired correctly, the problem is probably in the alternator with sticky brushes or a dud diode.

 

Do you still get 14volts with the headlight & aircon/fan on??

 

Where does the wire with the inline fuse go?? Is it the yellow/white line that goes to the ign light? Although there is no fuse in these diagrams....

 

I'm afraid my KE70 has a built-in regulator, so I haven't worried about one for years.

That doesn't sound like the starter return!! There should be a strap from the motor to the body or battery that is the same thickness as the battery +ve to the starter. That is the one that carries all the current.

 

Anyway, I feel your problem doesn't lie there... If your new voltage regulator is wired correctly, the problem is probably in the alternator with sticky brushes or a dud diode.

 

Do you still get 14volts with the headlight & aircon/fan on??

 

Where does the wire with the inline fuse go?? Is it the yellow/white line that goes to the ign light? Although there is no fuse in these diagrams....

 

I'm afraid my KE70 has a built-in regulator, so I haven't worried about one for years.

I guess I phrased that wrong, I just want to know the stock connection points for the grounds. It just looks terrible sitting on top of my engine.

Anywhere will do...

 

A fat one off the starter mounting bolt back to the body, then from there to the battery, or starter straight to battery just like the +ve, with a 6mm or 8mm wire from the body to the -ve.

 

I set it up like this: red is +ve going under the radiator to the starter, yellow comes off the motor to the battery -ve, and green goes from the body to the -ve.

 

The rest of the wiring comes off the starter +ve terminal where that red cable bolts on.

Got it figured out, I ran the ground and engine strap down to the drivers side mounts and bolted them up. Also I fixed the charging light issue by putting a random 2.5 amp fuse in the yellow wired fuse holder. So thats all tucked away now and I'm onto the next project. :dance: