Recently I solved a problem which was when I turn my headlights on my turn signal indicator lights, my rear defrost switch light, my high beam indicator light would come on but my headlights wouldn't. I fixed this by creating a better ground for my headlights and it solved all those problems. Now this morning I turned the truck on and as soon as I turned my headlights on the truck instantly died and now it won't start. I don't even have power to the starter. I'm wondering what the headlight switch could have to do with killing the engine? One more thing to throw in the mix. I put a vortec motor in the truck so this isn't all original Land cruiser wiring. I'll check my fusible links and I'll check my neutral safety switch. But the peculiar thing of the headlight switch killing the engine I'm wondering what insight you might have?
Turns off when I turn the headlights on (1 Viewer)
- Thread starter PanhandleFJ
- Start date
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I dont know what is going on in your circuits....but can it be that there is a bad connection at the battery or battery cables? A bad connection somewhere (ground or positive) can be good enough to power small electrical consumers but the headlamps with their higher demand of ampere could overstress that bad connection and it is loosing all its power transmitting properties. It can be "weld" together again any moment...and then by bad again.
Just a thought.
Just a thought.
- Thread starter
- #3
I think yes that's a possibility. I'm wondering why would a headlight circuit be interfaced some how with the circuit that would keep the engine running? It seems like a bad design. I have the utmost respect for the electrical engineers of the Landcruiser and I'm pretty ignorant about the design.
diesellibrarian
SILVER Star
It sure sounds like fusible links.
Your initial problem of other lights coming on when turning on your headlights suggests a ground fault. 60 series circuits are usually ground-switched, which means that the switch is located after the load (eg light) on the circuit (as opposed to my old VWs, for instance, which were hot-switched, meaning that the switch is between the battery and the load). The advantage of a ground-switched circuit is that if the switch fails or a connector comes loose and shorts to ground, all that happens is the light turns on. If hot-switched switch fails or shorts to ground, you'll have a very high-amperage short and that's when you see things like melted wires and various things welding themselves to other things haha.
I'm wondering if there are hot-switched circuits in the Vortec harness that are not playing nice with the ground-switched wiring in the rest of the truck.
There are a couple of common grounds under the dash that can be damaged (i.e. fried) by a short circuit. When that happens, resistance is created at the ground, and the current will seek a path of less resistance, which is sometimes through other circuits at that common ground. Adding a new ground created a less-resistant path, which fixed your headlight issue. A short anywhere along the line could easily have overloaded any of the circuits in your truck, with the fusible links perhaps giving their lives to save your wiring harness?
I'm not an expert and I'm just spitballing here, but them are my two bits.
Your initial problem of other lights coming on when turning on your headlights suggests a ground fault. 60 series circuits are usually ground-switched, which means that the switch is located after the load (eg light) on the circuit (as opposed to my old VWs, for instance, which were hot-switched, meaning that the switch is between the battery and the load). The advantage of a ground-switched circuit is that if the switch fails or a connector comes loose and shorts to ground, all that happens is the light turns on. If hot-switched switch fails or shorts to ground, you'll have a very high-amperage short and that's when you see things like melted wires and various things welding themselves to other things haha.
I'm wondering if there are hot-switched circuits in the Vortec harness that are not playing nice with the ground-switched wiring in the rest of the truck.
There are a couple of common grounds under the dash that can be damaged (i.e. fried) by a short circuit. When that happens, resistance is created at the ground, and the current will seek a path of less resistance, which is sometimes through other circuits at that common ground. Adding a new ground created a less-resistant path, which fixed your headlight issue. A short anywhere along the line could easily have overloaded any of the circuits in your truck, with the fusible links perhaps giving their lives to save your wiring harness?
I'm not an expert and I'm just spitballing here, but them are my two bits.
- Thread starter
- #5
That's some great spitballing, thanks. I'll check to see what circuits I've crossed paths with on the LC. I also purchased some Torfab LED headlights that I'll be installing this weekend so I'll be into all the wiring. I appreciate your response.
