Hi, okay, so I have a 1987 Ford Thunderbird, and a few wires on the top connection got hot enough to blacken the wires. Yikes!

Gladly, nothing caught on fire.

so now, what could be wrong? My guess is that the wiring harness connector tot he multifunction switch is not making a great connection, which is causing arcing and heating up the unit. The fuses have not blown, so I don't think it is a short. I think it is arcing. **

I can get the wiring plug, but I want to understand what the wires are doing.

From Haynes,

• Red/Black - Low Beam (per Haynes)
• Red/Yellow - Hot from Headlight Switch (per haynes)
• Yellow - High Beam (goes to LG/BK wire eventually, per haynes)
• Red - goes to Flash to Pass relay (per Haynes)

But the others are unclear to me.

On the top connection, there are the following:

• Red/Black
• Red/Yellow
• Yellow
• Red
• Green/White x2
• Light Green/Orange

On the bottom connection, there are the following:

• Orange/Blue
• White/Blue
• Light Blue
• White/Red
• Light Green

Any help? I'm actually wondering if I can just connect the Red/Yellow directly to the Yellow (for only high beams), or the Red/Yellow directly to the Red/Black (for only low beams). The "high beams" are set low enough to not interfere with oncoming traffic, and I use aux lights for highway driving that I turn off in the city.




** Actually, the instrument panel fuse (5A) has blown twice in a week, but I think that is unrelated to the multifunction "melt down" issue.

 

Mark I don't know how much this will help since the info came from a 91 T bird diagram.

Wht-Lt Blu=R/ dir sig & stop
Org-Lt Blu= R/R dir sig & stop
Lt Grn- Org= L/R stop/sig
Lt Grn-Wht= L/F dir sig
Red-Blk = Low Beam
Red = Hi beam
Red-Yel headlite sw to flash to pass sw
for Low beam Red-Yel supplied Red-Blk
For Hi Beam Red-Yel supplied Red wire to Hi Beams
If more help required let us know .
That 5 amp fuse that is blowing may be the supply to the dimmer section of the lite switch a Lt Blu- Red wire.
Are the wiper switch wires all OK ?

 

Hi, thanks so much!

So it turns out the Red/Yellow is hot, and the Yellow is high beam, this is strangely different than yours. I hooked those two together and all is well. The Yellow & Red/Yellow connectors in the assembly were melted. I twisted them together, then heat shrunk them.

I reattached the upper assembly, and tested the blinkers -- everything works perfectly.

On the 5a fuse, I replaced it again and it has been working for a week with no issues.... so I'm not sure what to say to that right now.