pcsteve70 Posted October 9, 2023 Share Posted October 9, 2023 I have 1986 F250 king cab 2WD. The dash lights and turn signal lamps stopped working. The gauges work fine. The switch for the headlight/dimmer was replaced. The new switch is an 8 pin the existing switch was clearly burnt up and it was a 7 pin. NAPA stated this was the direct replacement. It fits and works the headlights operate on/off but I get no instrument cluster lighting HVAC control lighting or the headlight windshield knob lighting. I removed the cluster, changed out all of the lamps to new standard incandescent. I did get teh high beam indicator to work and both turn signals. But none of the other lamps in the dash operate. The dome light does work and the exterior marker lights and headlamps operate. I get voltage on the circuit board to the lights I describe that work but no voltage to any other lamps. I cant tell if this is a combination of a ground or fusible link issue potentially. I have checked all of the fuses and they are all good. Any assistance to steer me would be appreciated! Link to comment Share on other sites More sharing options...
Gary Lewis Posted October 9, 2023 Share Posted October 9, 2023 Welcome to the site. But you apparently missed Jim's email asking you to go to the New Members Start Here folder and post an intro there. Don't worry as many have missed that before. We ask that because we host the guidelines there and since we hold everyone to them we want you to have had every opportunity to have read them. So please read the guidelines and let us know that you have before we get into the instrument lighting discussion. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 9, 2023 Share Posted October 9, 2023 It's all good now. Carefully look at the wires coming from the plug of the headlamp switch. If they get overheated and melt they can short or fail open. You can get both the 7&8 pin wiring pigtails from Pico. https://www.picowiring.com/catalog.html Link to comment Share on other sites More sharing options...
pcsteve70 Posted October 9, 2023 Author Share Posted October 9, 2023 It's all good now. Carefully look at the wires coming from the plug of the headlamp switch. If they get overheated and melt they can short or fail open. You can get both the 7&8 pin wiring pigtails from Pico. https://www.picowiring.com/catalog.html Thanks Jim! yeah I went through it pretty good. I have a new 8 pin switch. The headlights work now as do the indicators up at the cluster. Just nothing else. All of the lamps are new and I tested the circuit board on the cluster. I do not have any voltage to the pin connector or any of the lamps so I do not think it is a ground issue. Just lost power somehow. I'm heading back out now to start over.. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 9, 2023 Share Posted October 9, 2023 Thanks Jim! yeah I went through it pretty good. I have a new 8 pin switch. The headlights work now as do the indicators up at the cluster. Just nothing else. All of the lamps are new and I tested the circuit board on the cluster. I do not have any voltage to the pin connector or any of the lamps so I do not think it is a ground issue. Just lost power somehow. I'm heading back out now to start over.. So is it just the cluster? Do you have illumination of the climate control, radio and headlamp/wiper switches? If so, that points to the plug on the back of the cluster or the flex circuit. Link to comment Share on other sites More sharing options...
pcsteve70 Posted October 9, 2023 Author Share Posted October 9, 2023 So is it just the cluster? Do you have illumination of the climate control, radio and headlamp/wiper switches? If so, that points to the plug on the back of the cluster or the flex circuit. No, the wiper knob light, the climate control lights and all of the "Blue" back lights at the cluster are dead. Just found that I have no voltage on the 5 amp cluster illumination space on the actual fuse block. I am tearing the fuse block out now. May be the source of the gremlins. Ill let you all know ! Thank you Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 10, 2023 Share Posted October 10, 2023 No, the wiper knob light, the climate control lights and all of the "Blue" back lights at the cluster are dead. Just found that I have no voltage on the 5 amp cluster illumination space on the actual fuse block. I am tearing the fuse block out now. May be the source of the gremlins. Ill let you all know ! Thank you That 5A fuse is powered by the Lb/R wire (circuit 19) coming from the wire wound rheostat on the headlamp switch. If you don't have power to either side of the fuse check continuity from the switch connector to the panel before pulling everything apart. Link to comment Share on other sites More sharing options...
pcsteve70 Posted October 10, 2023 Author Share Posted October 10, 2023 That 5A fuse is powered by the Lb/R wire (circuit 19) coming from the wire wound rheostat on the headlamp switch. If you don't have power to either side of the fuse check continuity from the switch connector to the panel before pulling everything apart. ok I checked the headlight switch. When powered on it sends voltage to the 5A fuse block. The block is fine. Its after the fuse block. I traced the the power out of the fuse block into the harness. It leaves on a blue wire with pink tracer. I believe it is "supposed" to land on terminal 5 up at the cluster pin. But it has no power there or at any of the climate lights or wiper knob light. Somewhere there is a splice or relay. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 10, 2023 Share Posted October 10, 2023 ok I checked the headlight switch. When powered on it sends voltage to the 5A fuse block. The block is fine. Its after the fuse block. I traced the the power out of the fuse block into the harness. It leaves on a blue wire with pink tracer. I believe it is "supposed" to land on terminal 5 up at the cluster pin. But it has no power there or at any of the climate lights or wiper knob light. Somewhere there is a splice or relay. If you have none of those lights it has to be between the fuse panel and splice 806. Splice 806 is listed as (Taped Over) 'near heater control switch' Link to comment Share on other sites More sharing options...
pcsteve70 Posted October 10, 2023 Author Share Posted October 10, 2023 If you have none of those lights it has to be between the fuse panel and splice 806. Splice 806 is listed as (Taped Over) 'near heater control switch' yep..thank you for the diagram! I also think I may have a bad "new" switch from NAPA. Now the blue wire with tracer that was hot when the lights were turned on is dead and so is the fuse block. So Ill grab one tomorrow to be sure. Thank you so much for your help. Ill hit it again after work tomorrow. Link to comment Share on other sites More sharing options...
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