Skip to main content
Topic: Alternator wires? (Read 7227 times) previous topic - next topic

Alternator wires?

On a 87 t.c the green wire at the alternator that goes to the gauge I read that it is hot on key but should it be ground on key off?
[SIGPIC][/SIGPIC]:ford:87 Turbo Coupe through the floor sub frame connectors, 5.8 swap Ford racing heads Harland sharp 1.6 rockers BBK shorty swap headers 2 1/2 BBk X pipe magnaflow ler's. Megasquirt 2 with 36lbs injectors on hurricane intake with 4150 throttle body.Tremec TKO 600 Quicktime blowsheild spec stage 3 clutch. 3.73 gears and still not done

Alternator wires?

Reply #1
No.
Why do you ask?

Alternator wires?

Reply #2
OK here is the circuit build

C311-38-BK/O goes to S262out from shunt R/LG  to Shunt 37-Y.  C310-36-Y/W Goes to S269 20GAUGE fuse link BLUE Fuse link In portion of Shunt 37-Y. Another words both have battery on them across the ammeter shunt. Hope this helps


87 TC revision to alt lead 17645    Green or LG/R 904 to 20 GAUGE fuse link-K to ignition switch RUN. Yes this lead will have Ground on it with the key off and battery on it with key on.
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

Alternator wires?

Reply #3
You are correct that my post was probably misleading. A lack of voltage looks the same as ground on a volt meter.
I was hoping he would respond with more detail about his problem


Alternator wires?

Reply #5
I'm chasing a parasitic loss. With the alt plugged in I'm pulling 12.5 volt with a meter in line with the pos post. Unplugged it drops to .43 volts.  Wanted to know what's what with the plug before I jump on the guy who rebuilt my alt
[SIGPIC][/SIGPIC]:ford:87 Turbo Coupe through the floor sub frame connectors, 5.8 swap Ford racing heads Harland sharp 1.6 rockers BBK shorty swap headers 2 1/2 BBk X pipe magnaflow ler's. Megasquirt 2 with 36lbs injectors on hurricane intake with 4150 throttle body.Tremec TKO 600 Quicktime blowsheild spec stage 3 clutch. 3.73 gears and still not done

Alternator wires?

Reply #6
then start unplugging one output connector at a time on the alternator,, or at best,,,

-remove every wire / ring lug at the starter relay
-connect one wire at a time until you see the voltage reappear.
-once you determine which wire is the cause, it will send you to the downstream fault.

Typically we tend to jump on the voltage regulator,, which could still be the fault.

Are you a 3g upgrade?
if not
are you unplugging the regulator connector or the alternator ouput connector making the 12v go away?

Alternator wires?

Reply #7
Take the negative battery cable off the battery. Hook a test light between the negative battery cable and the negative battery post.
If it lights, you have a battery drain.
Disconnect stuff until you figure out which wire lights the light.
A good place to start is at the starter relay. Take all the wires off the terminal that the positive battery cable goes to.
If the light goes out, put the wires back on one at a time starting with the pos battery cable.

Alternator wires?

Reply #8
Its 3g Ive gone through the fuse panel Ill try the rings on the starter solenoid in the am.
[SIGPIC][/SIGPIC]:ford:87 Turbo Coupe through the floor sub frame connectors, 5.8 swap Ford racing heads Harland sharp 1.6 rockers BBK shorty swap headers 2 1/2 BBk X pipe magnaflow ler's. Megasquirt 2 with 36lbs injectors on hurricane intake with 4150 throttle body.Tremec TKO 600 Quicktime blowsheild spec stage 3 clutch. 3.73 gears and still not done

Alternator wires?

Reply #9
ahh,,, well now, since removing the fuses did not make the issue go away, then its an upstream problem closer to the battery and not a downstream device.

Not looking good at all for the voltage regulator.

Those are not cheap nor is a 3g alt.
I about ped when (on mason's bird) i discovered how expensive the 3g's are.

Alternator wires?

Reply #10
just fyi, not every single thing is fused in our cars, ,although the intent was to add fuse links to devices that it was not practical to fuse,, they fail in my opinion to serve as a fuse for what a fuses call to duty is suppose to be.

Thunderchicken solved this and many other qurky wiring issues with a relay / fuse bank,,, which I think is great if your good at wiring.

You started off right but you should have started at the starter relay first,, lesson learned though, getting at each fuse is a pita i know.

Alternator wires?

Reply #11
Its been a long learning experience I'm told I'm good at wiring I can understand a semi complex circuit. All my friend come to me for wiring help but oh how I Hate wiring Ive started soldering and shrink tube on all connections where possible.
By the way glad to see your back JCassity.
[SIGPIC][/SIGPIC]:ford:87 Turbo Coupe through the floor sub frame connectors, 5.8 swap Ford racing heads Harland sharp 1.6 rockers BBK shorty swap headers 2 1/2 BBk X pipe magnaflow ler's. Megasquirt 2 with 36lbs injectors on hurricane intake with 4150 throttle body.Tremec TKO 600 Quicktime blowsheild spec stage 3 clutch. 3.73 gears and still not done

Alternator wires?

Reply #12
Quote from: softtouch;364319
You are correct that my post was probably misleading. A lack of voltage looks the same as ground on a volt meter.
I was hoping he would respond with more detail about his problem

 
Actually when you look at circuits that are not powered up they will be grounds because their is no current flow. Example if ypu remove a FUSE on a device and hook your Test light to battery and back probe lets say a blower circuit it will act like a ground because thats what it is. The blower motor has low resistance and will light the Test light easily. This stumps many a novice when trouble shooting. I am not saying you are a novice i am talking in general. Normally walk away drains are best shot with a test light in series with the negative battery terminal. But you must use a conventional test light not a circuit safe one. Then do a MILLI AMP drain test to calculate exact shutdown drain. Thanks. His initial question was the green wire that does not terminate at the ammeter. It is key battery through a fuse LINK. Thankss
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

Alternator wires?

Reply #13
Quote from: thewestie;364344
Its been a long learning experience I'm told I'm good at wiring I can understand a semi complex circuit. All my friend come to me for wiring help but oh how I Hate wiring Ive started soldering and shrink tube on all connections where possible.
By the way glad to see your back JCassity.

Hang in their it takes years to learn. I have been doing it all my life and still learning. Soldering is the key until they ban the stuff. Here is a tip!!!! Stock up on 60/40 solder flux core they are going to ban it. All car manufacturers cant build cars any more using solder its illegal. Everything is CRIMPED. I was told this by a couple of GM engineers.
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

Alternator wires?

Reply #14
The regulator draws current even when the car is off. You have to use a milli amp meter to check it properly. All cars draw down some thats the nature of the BEAST now. Radio memory seat memory ETC. New cars draw up to 200 Milliamps. They eventually run the battery down if not started. Good luck and have a good night
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!