One of the grounding junctions for the headlights is behind the gauge cluster. The entire gauge assembly needs to come out to gain access to it. On this model year, the ground junction is the small orange thingy with the green arrow pointing at it.
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This picture below shows the wire junction pulled out a bit to gain access to it. A burnt spot can be seen. This looks mighty suspicious. The blue wires are all connected to each other and the white/black wires are all (supposed to be) connected to each other, but the blue wires are kept separate from the ground wires by this special plug. It is not a single connection spot, but two.
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Picture shown below shows the culprit. Obvious problem. This was the gremlin for all the weird headlight and dash indicator strangeness... one bad ground connection in this junction.
All the white/black wires were removed from this connector and were cleaned up and all joined together and connected with a jumper to a known good ground to test if this was the problem.
It was.
Testing grounds
All the dash indicator lights then worked perfectly as did the headlights after this ground wire connection was fixed.
>>>>
Ultimately the question may be asked, "why did this happen?"
25 years ago, high wattage H4 halogen headlamps were installed without upgrading the wiring harness with remote relays. The increased amp draw was beyond what the stock wiring and connectors were designed to carry.
The increased current found a weak link in this grounding connector that only uses tiny sliding pins as junctions. The increased resistance at this poor-contact, pin to pin junction created excessive heat, which melted the plastic, creating carbon, coating the metal pin and female connector with insulating contaminates.
Lesson learned from this particular problem:
Always upgrade the lighting wiring harness with remote relays if upgrading to higher wattage headlamps... & it is a good idea to do so anyway if the stock sealed beams are retained.
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This picture below shows the wire junction pulled out a bit to gain access to it. A burnt spot can be seen. This looks mighty suspicious. The blue wires are all connected to each other and the white/black wires are all (supposed to be) connected to each other, but the blue wires are kept separate from the ground wires by this special plug. It is not a single connection spot, but two.
---------------------------------------------------------------------------------------------------------------------
Picture shown below shows the culprit. Obvious problem. This was the gremlin for all the weird headlight and dash indicator strangeness... one bad ground connection in this junction.
All the white/black wires were removed from this connector and were cleaned up and all joined together and connected with a jumper to a known good ground to test if this was the problem.
It was.
Testing grounds
All the dash indicator lights then worked perfectly as did the headlights after this ground wire connection was fixed.
>>>>
Ultimately the question may be asked, "why did this happen?"
25 years ago, high wattage H4 halogen headlamps were installed without upgrading the wiring harness with remote relays. The increased amp draw was beyond what the stock wiring and connectors were designed to carry.
The increased current found a weak link in this grounding connector that only uses tiny sliding pins as junctions. The increased resistance at this poor-contact, pin to pin junction created excessive heat, which melted the plastic, creating carbon, coating the metal pin and female connector with insulating contaminates.
Lesson learned from this particular problem:
Always upgrade the lighting wiring harness with remote relays if upgrading to higher wattage headlamps... & it is a good idea to do so anyway if the stock sealed beams are retained.
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