I have no headlights,taillights,nothing but turn signals.
Wires shorted out at dimmer switch maybe?
Any ideas. ANYBODY,
Have lost several circuits, this is not a diagnosable by internet problem. Find a mechanic that has electrical troubleshooting skills is your best bet.
That's what I did last week but so far he hasn't touched it. I talked to an old friend of mine that is retired and he told me to start with the switch as well,so I might go get it and try that if the shop doesn't get started soon.
Is there power at the headlight switch? I would expect two power supply wires one for headlights and one for park lights.
Should be Battery at the fuse block, that feeds out on different contacts to the headlight switch then to the lights. Fuse slots should be marked as I remember as to Lighting Circuits.
One problem those IH's had was corrosion at the main bulkhead connection on the engine side of the firewall.
100% agreement. The male/female spade connections and the block were not well protected against moisture. Additionally , added circuits like dash mounted fans, extra running lights etc would overtax the connection and loosen the female spade with excessive heat. ALSO recommend looking closely at the headlight switch itself. Those old ones supported 100% of the load, no relays. It may be a burned/loose connector assembly as well. I seem to recall that same switch and circuit used up till 90-91? Somewhere in there, when they switched to low current switches with load carrying relays. Good luck.
No power at the switch
Do you know if the fuse blocks are still available from International? If not would it be possible to retrofit from a newer model? This is a really nice old truck otherwise and I need to get some lights on it. We did get blinkers and brake lights but no fire at the headlight switch.
I imagine someone still has new old stock. Napa used to be a good source for terminals. The blocks are usually ok, it's the terminals are usually burnt or loose.
Navistar Corn Queen Dealers can still get most parts for these, know the one at Jefferson City got pieces for a F2575 a logger here uses.
I could not find any fire at the switch. I was wondering if I could run a hot wire straight to the switch from the mattery and put an inline breaker in it?
I guess I need to start proof reading, that was supposed to say BATTERY not mattery.
Better off taking down the fuse block, inspect the Backside locate the real problem. It will just be a start as to wiring go dead to each function if don’t. Also lays the groundwork for incidental fires on backfeeds into the old wiring running new circuits. The memory of “I run a new wire cuz the lights quit working”, where had birds nests of that style repair to wade thru and find real issues.
If I had to rewire, I'd probably just go and get a generic fuse/relay block from Painless and wire it all up myself.