With the gauges sorta done (I believe I will do a nicer version in the future), it was time to finally wrap up the rest of the wiring. One area that I knew was going to be bad was the cowl lights. This was the only part of the entire truck that had any serious rust. The light housings themselves were OK, but the inner reflectors (that the bulb sockets snap into) were completely shot:
I was going to try to make my own, but then I discussed it with my son Brian and he told me to give him one of the rusty old reflectors and leave it with him. Not long afterwards, he surprised me with these:
He used the 3D printer to whip up a set of new reflectors. For a shiny backdrop to reflect light I simply used shiny silver spray paint. The original cowl lamps were just parking lights with a single contact bulb. The squeeze style of socket for the bulb is still available (Dorman model 85804, a whopping $1.81 at Rockauto!), however a dual contact plug is also available (Dorman model 85802). By switching to the dual contact plug, and using miniature bulbs (Wagner B1007) that fit inside the very limited space, I was able to convert the cowl lamps to be both parking and signal lights. It was actually quite easy, as the S10 harness obviously had provisions for both, so it was simply a matter of routing the existing wires to the cowl lamps and adding a 3rd wire to each socket in order to provide a proper ground. This was necessary as the new reflectors are ABS and won’t allow the cowl lights to body ground as they were originally designed to do. Here’s the old vs the new:
The headlight pods were in good shape, so all I did was clean them up, retap all the holes and put in new 12 volt sealed beams and new sockets. I’m adding weatherproof quick connectors as well for a very good reason. The engine in this thing is fairly buried, and even simple jobs like changing spark plugs would involve some fairly miserable leaning over and trying to access things. With the front fenders off, access is fantastic and comfortable (I can actually pull up a chair and sit and work on the engine). Removing the front fenders on this thing is painfully easy (it’s just a few bolts), so adding a way to unhook the headlights (which are mounted on the fenders) makes it ever so easy to pop off a fender in a minute or two.
At the tail end I did the same thing so that I can remove fenders and bedsides easily. I also wired in weatherproof connectors for reverse lights. At night it’s pitch black here (I need a flashlight to go from my shed to my house), so decent reverse lights are a must.
At this point I had working exterior lights, and now it was time to instal a single old-style headlight switch to replace the S10 switches. The S10 has a big, ugly, plastic toggle and dial combo switch, Ugh!!!!:
I dreaded this wiring task, but as usual my imagination made it out to be far more difficult than it actually was. I’ll detail what I did here, along with an explanation in case anyone else doing an S10 swap could use a short guide. Remember that this is a 1996 S10 so other years may differ. As well, a wiring diagram is an absolute must for this kinda fooling around!
The S10 switch is actually 2 switches-one for lights and one to dim the instrument panel. Here is the headlight switch, with brown, red, yellow and 2 orange wires (the 2 orange wires actually share the same connector pin):
The replacement headlight switch I chose is for a 1970 C10 but the same (or pretty much the same) switches were used over a huge time frame by GM. The spade connectors are numbered on the switch. Here’s what I did:
The big red wire in the S10 switch gets power from a fusible link. I removed this from the S10 switch and installed it in location #1 on the new switch.
The brown wire in the S10 switch feeds everything but the headlights. I removed the brown wire from the S10 switch and attached it to position #4 on the new switch.
The S10 switch has a double orange wire (2 orange wires enter together at the same pin). I removed these from the S10 switch and attached them in location #5 on the new switch.
The yellow wire in the S10 switch powers just the headlights. I removed this and attached it to location #6 in the new switch.
For the cowl lamps (which are now dual filament bulbs to provide parking and signal lights) it got a little more interesting. My cowl lights are white, so they are not allowed to be on while the vehicle is in motion (only a problem at night when the headlights are on). To power the parking lamp filaments of the cowl bulbs, I cut the brown S10 wire that feeds them at the main firewall pass-thru, and ran a fresh brown wire to them from location #7 on the new switch (this position only has power when the knob is pulled out to the first detent).
The S10 instrument panel dimmer dial switch has 4 wires, and it controls both the on/off of the dome light and the dimming of the instrument cluster lights:
By removing the white wire from the S10 instrument panel dimmer switch, and connecting it to position #0 on the new headlight switch, the dome light works. The black wire on the S10 dimmer switch is just a ground that isn’t needed. I am keeping the entire S10 dome light assembly as the Fargo one was trashed. The other 2 wires from the S10 instrument panel dimmer switch (brown and dark green) control the dimming of the instrument cluster lights. I only have 3 small bulbs in my gauges, so after cutting out the S10 instrument panel dimmer switch I simply connected the brown to the dark green wires, thus giving me a full 12 volts to those lights. If I had wanted the dimming feature, it would just be a matter of attaching the dark green wire from the S10 dimmer switch to location #2 on the new headlight switch.
Here’s a shot of the process as I was figuring things out:
I did it one wire at a time, and I confess that I flinched every time I reconnected the battery (I fully expected to blow some fuses as electrical stuff is not my strong suit). After each wire was installed and the battery reconnected I switched stuff on and off and made sure that everything was still OK. 6 wires later I was all done and everything worked.
More to follow!