I'm looking for a wiring diagram for an 1988 s1954 truck, cab wiring to be specific. Parking brake warning light - brake pressure warning (assume this is the hydraulic reservoir is empty, but not sure) light don't work. Also found wire 63 and 63a broken off in the junction box behind the seat. I'm not sure what they're for. Dome light don't work via the headlight switch, none of the cluster lights work. Figured I'd ask here if anyone had a diagram before I tear everything apart and have to do this the hard way. Its simple enough wiring but the thing is, everything in the cab seems to be black wires with numbers written on them. Not the easiest to track down.
That is standard procedure for IH going back into 50's early 60's. White liked to use all White with #'s, common. There are a few on here that can provide some wiring diagrams, IIRC.
In the event that anyone comes along in the future.. 63 and 63a seems to be the dome light control and power, the dash switch provides ground when the knob is turned full left. I'm stumped on the cluster lights, I removed the bulb and tested both terminals and they're both grounded. I unplugged the headlight switch completely and both were still grounded. I did the same with another bulb at the heater control and found the same. Plug for the headlight switch has melted at some point, looks serviceable still though. I gave it the jiggle test and didn't see any changes. I guess the + side of the circuit must be grounded somewhere. Weird that its not blown a fuse that I can find.
I think I would be checking relays.
I've found 2 metal mystery boxes in the drivers footwell, next to the headlight dimmer switch and they have 3 terminals on each box. I thought they were relays but I don't recall ever seeing a 3 wire relay. 1 of the boxes was unplugged so I connected 1 (there's 2 in the vicinity) of the connectors, When I turned the key on it made a terrible racket. I kind of thought it was a buzzer. I haven't found anything else that I recognize as a relay. There is a solenoid on the inside of the firewall that seems to control the engine off hydro boost pump and another solenoid on the outside of the firewall that I haven't figured out what it controls.
It looks like all the service data for that vintage of truck has been dropped from the Navistar website. Some older Internationals had a solenoid on the firewall that was the ignition power relay for the electrical system. I see a few wiring manuals for the S series trucks for sale on Ebay.
Looks like Ebay may be my only choice at this point for a diagram. I've been searching for a few days already and can't find anything online. I'm finding stuff thats just left unplugged and I'm sure some of it goes to an air brake truck or for some option that I don't have but makes it hard to figure out what goes where.
Thanks much!
Damn I forgot Spud has a barn yard Cadillac, good job spud.
No problem, I got 3 books on that rig. Thanks, I had to crawl through shipping container trying to find the book or I would of gotten the answer out sooner. Tad bit warm and smokey here, not easy being outdoors much less in a shipping container. Swore I was going to be smoked human jerky before I got done.
Thanks for risking your life to help me out, hahaha. Is barn yard Cadillac what you guys call these international trucks?
Oh I'm messing with you I have handled worse conditions for longer duration's, no big deal. I have always heard corn queens.
It's a old term-I call them Corn Queens or what ever comes to mind at the moment and that goes for all trucks, you open the hood in the morning pour a sack full of money under there shut the hood and drive away and repeat the process the next day and day after that.
Lol sounds about right, I've done a lot of cleaning on mine so far, replaced the hydro booster because it was leaking inside and outside the firewall. Torn out the carpet in the cab, cleaned, degreased inside. Alternator belts replaced, stretched. Flushed the power steering system, was some nasty fluid. Probably some other stuff I've forgot.
We have dash lights. Thanks
Would you happen to have a diagram for a 78 F-2574 ? I have a book that I bought on eBay and the fuse block isn’t the same, I think the book is for a later model but there’s no date on it.
What was the fix?
It was a combination of burned out bulbs and bad connections between the socket and circuit board.
That wiring diagram Spud posted is funny, I bet my electric toothbrush has more components that that. Joe H
I love the simplicity of these trucks. Thing is, all the wires are black. The only way you can tell which wire goes where is by the numbers printed on the wire. In my case I had a bunch of wires laying in places that were disconnected so no idea where they were supposed to go or do.
I worked on a 80's paystar to fix the lights. The wiring diagram was under the pass seat facing out and was super easy to follow. The wiring junctions under the hood on both sides and the back was super easy to check all the connections. The previous guy replaced the blinker switch and mixed and matched all the wires under the hood. I tried them back straight and poof everything worked, including the old blinker switch. Easiest truck I ever worked on.
Iv been thinking the same.. I have the exact issue. Even the same disconnected interior light wires behind the seat. I was thinking bulbs and maybe where the wires plug in on the firewall under the hood . Were both headlights burnt?
International is referred to as 13 Letter **** Spreader around here.
Could anyone give me a wire numbers list or schematic of a 1978 s-1824. Can't imagine why but former owner cut off the wires on the harness. I guess the original engine was gas and now a DT466.