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84 Charging problem with melted wires

Hi need help. I have a 84 tbird with 5.0l All stock. I had charge light come on and got home to find the wht/black stripe wire from alt connector melted this wire goes to volt reg and the other wire from the reg same term goes into harness and across front of car and melted about 2 feet of that too? I changed volt reg a while back. What is this wire for and what caused this? Going to have alt checked for over voltage of something?
Thanks
Ken

84 Charging problem with melted wires

Reply #1 –
The W/BK wire is the Stator voltage output from the alternator.
It causes the Regulator to turn off the alternator warning light when the alternator has output.

Where else does it go is the important question, because that seems to be where the overload is.
If you have a carburetor it goes to the choke heater.

The 84 EVTM also shows it going to the VIP test connector. That's the connector where you pull codes. I looked at my 84 3.8 and there is no W/BK wire on my test connector.

If it's not raining tomorrow I will see if I can physically trace the mystery wire.

Cut the wire going into the harness and just leave the connection between the Alt and The Reg. The Stator voltage should be half the Alt output voltage, around 7 volts.
Hopefully it hasn't blown the Alt.

84 Charging problem with melted wires

Reply #2 –
I was thinking about leaving the all white wire that goes into the harness off also.
I just got the alt out and the wire from the stator is melted there to the connector also.
Anyone know where to get a new harness with connector?
I'm going to replace alternator and fix wires and see what happens.

Any other suggestions please?

84 Charging problem with melted wires

Reply #3 –
update.
The other wire is white with pink dots goes from same term as wht/blk from stator to voltage reg (there is two wires from this term on volt reg) and goes around front up drivers side across back and into firewall on pass side. My guess is this is the dash light wire?

Hopefully the alt is causing the over voltage on the stator

84 Charging problem with melted wires

Reply #4 –
Quote from: kmhracing;314308
update.
The other wire is white with pink dots goes from same term as wht/blk from stator to voltage reg (there is two wires from this term on volt reg) and goes around front up drivers side across back and into firewall on pass side. My guess is this is the dash light wire?

The EVTM shows this wire as also being W/BK. Discrepencies between the EVTM and the real world are not uncommon. This is not the wire to the dash light. That would be the LG/R wire from the "I" terminal on the Reg.

Quote
Hopefully the alt is causing the over voltage on the stator

You say the wire from the Alt Stator terminal to the "S" terminal on the Reg overheated and the wire from the Reg "S" terminal to where ever (mystery wire) also overheated.
If this is true, the problem is the mystery wire or whatever it is hooked to.
The Alternator did not cause the problem but it may have been damaged by the problem.

EVTM Diagram:

84 Charging problem with melted wires

Reply #5 –
Thanks the diagram is a help. I don't see how the other white wire goes to the test connector? I'm rebuilding the harness and leaving off the wire to choke heater and to "test connector" and replacing alt.
See how this goes?

Anyone know where to get the three wire alt connector or the press on stator/field connectors with the boots?

Also anyone know if the 3G upgrade will work on this car? No surp belt?
Does the alt spin the same? 84 bird 5.0L

84 Charging problem with melted wires

Reply #6 –
Quote from: kmhracing;314477
Anyone know where to get the three wire alt connector or the press on stator/field connectors with the boots?

The stator wire on my Alt has a ring connector and a nut.

Quote
Also anyone know if the 3G upgrade will work on this car? No surp belt?
Does the alt spin the same? 84 bird 5.0L

Yes you can do the 3G upgrade and it is driven by the serp belt the same as your 1G.
If you do the upgrade the connectors will be different. The 3G has an internal voltage regulator.

I traced the extra W/BK wire from my 84 3.8 Reg "S" terminal. It goes through a 12 pin connector behind the left headlight and through a 4 pin connector by the left strut tower. The wire goes about 6" past the 4 pin connector and ends there. Not connected to anything. This near where the test connector is on my car.

This is a CFI and not a Carb car correct?

Can you tell me if your test connector is gray or red? and what color the wire is in the "fuel pump" position. See pic below.

84 Charging problem with melted wires

Reply #7 –
Yea no carb it's FI

I don't have a surp belt it's old style. belt goes around crank, air pump, alt.

Will the 3 g still work. What should i get a alt from? I was thinking of this upgrade when alt went so now is the time if it will work on this setup?

Thanks still looking for the harness anyone have a connection?

Thanks,
Ken

84 Charging problem with melted wires

Reply #8 –
Missed your question.

The test plug is grey and fuel lead is Brown

Thanks for your help

Ken

84 Charging problem with melted wires

Reply #9 –
Quote from: kmhracing;314626
I don't have a surp belt it's old style. belt goes around crank, air pump, alt.

The rotation is the same. The parts store guy should be able to swap the old Alt pulley to the new one.

Quote
Will the 3 g still work.

Yes
Quote
What should i get a alt from?

I know some parts stores won't talk to you unless you have a make, model and year. Some people here have used Taurus alts, but I am not sure what year.
Quote
I was thinking of this upgrade when alt went so now is the time if it will work on this setup?


I have not bought one myself but I understand the 3G comes with the connector and pig tail wires for the Reg and Alt Stator.
If so this will save you from finding replacements for your burnt up stuff.

84 Charging problem with melted wires

Reply #10 –
You would splice the green/red wire from your old reg to the green/red wire to the new reg "I" position you see in the pic.

Most people who do this upgrade want to take advantage of the increased amperage capability of the 3G.
Your car has a black/orange wire that goes from the output of the Alt through a fuse link to the battery side of the starter relay.
They replace this with a 6 awg wire and a 120 amp fuse directly to the battery side of the starter relay.
You don't have to do this, or you can put it off until later.

Make sure you always disconnect the battery before doing any work in this area. Some of these wires are hot direct from the battery.

84 Charging problem with melted wires

Reply #11 –
I have been operating with my electrical blinders on.
If anyone has done a 1G to 3G please chime in.
Are there any mechanical problems with the mounting hardware?

84 Charging problem with melted wires

Reply #12 –
Quote from: softtouch;314818
I have been operating with my electrical blinders on.
If anyone has done a 1G to 3G please chime in.
Are there any mechanical problems with the mounting hardware?


This swap is scary easy on the early cars.

You just covered it in your post before this.

If you have the proper alt with the same mounting ear locations as the original, it is a drop-in deal.  I did the swap on my old '80 XR-7 with the 302, and it took more time to swap the alt pullies than it did to mount the alternator and do the wiring.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon
 

84 Charging problem with melted wires

Reply #13 –
Great thanks guy's.
I found a local guy that's very familiar with this. Stopped by his place today and he said the same thing very easy swap. He's going to get me some Good HD connectors.

I'm going this route and get rid of the old .

Anyone else chime in if you have more info.

As for the old alt connector/harness? I found nothing. Hard to find junk yard part.

I'll give this guy a plug Bear Auto Electric in Bethany, CT
Good guy,knowledgeable seems to be a ford guy too.