Hello all. Been watching and learning for awhile. But I've run into a snag and thought someone might have a couple ideas. I have a 84 chevy C60 that was a lumber truck turned into a grain truck (before I got it). Well with a little TLC I got the truck working pretty good, in July I used it at wheat harvest and everything worked good. The other day I decides to replace the boot that seals the gear shift and the floor board. In doing so I had to unplug the 2 speed switch from the wiring harness and in doing so 2 of the 3 post broke off. No big deal, I run to town get a new switch and wiring harness. Well as I'm look at the old harness wiring just below the switch someone spliced the wiring. So I unwrap the electrical tape and the wires were so bad it looked like someone stripped back 2 inches of bare wires layed them all together and wrapped it back up. My first thought was how in the world did this thing work in the first place. Well I pop the hood and trace the wires. A white wire to (power supply)a green wire to a post on fire wall marked LOW BEAM / 2 AXLE SPEED and a Black wire to a post on fire wall marked HIGH BEAM/2 AXLE SPEED.Thinking this shouldn't be a big deal. So I run the new wiring harness, mount the new switch.Give it shot and now the axle is in High side and won't go to low side. So I swap the green and black wire and then it goes in to LOW side but won't go into HIGH side. Well I thinking maybe I got a bad switch or wiring harness. So I unhook everything and use a voltmeter and check the switch and harness, everything is good. Well in unplugging the harness from the switch, the the top wire(Now a red wire in new harness) male post pulled out. The post and wire are still connected. So I just plug in the top wire and mount the rest of the harness to the switch. Turn on the key and push in the 2 speed axle switch and hear a whining.I pull it back out start the truck and begin to drive everything fine. I push in the switch let off the throttle and I hear and feel it going into LOW side. Think OK got it. Well I give it some more throttle and all of a sudden the axle shifts to the high side, I let off the throttle and it shifts back to the low side. What the heck?? Well I start thinking if that lose red wire post is shorting in and out on the 2nd post may be causing this. So I fix the harness to keep the red wire from shorting out. well I'm back to where I started, In HIGH side and won't shift into LOW side. So I get the volt meter and the red wire is hot all the time, with the switch pulled out the green wire read 11+ volts and 0 volts with switch pushed in. Black wire read 0 volts with switch pushed in or pulled out. I don't think this is right but I don't know what voltage I should be getting at each switch location(in and out). The only thing I can thing of is 2 of these wire from switch need to be wired together, but I'm not willing to start splicing wires together and blowing fuses, unless someone know for sure. Anyone got any idea's.I'm at wits ends with this thing.
Your wires are messed up. Check this with your meter, just the switch, with the knob pulled up the center pin and one end pin should be connected, with the knob pushed down, the center pin and the other end pin should be connected. Power should go to the center connection and feed out one or the other end. Both ends of the switch should feed back to the motor. Should have 12 volts plus, unless there's a bad connection somewhere else in the circuit.
I found one diagram: Grn = 12vdc Rd = high black = low, also to speedometer. Did you check the axle motor ground? Wire to frame. OOPS Lantraxco beat me!
Thanks guys I'll put the voltmeter to it tomorrow and check that ground while I'm at it.
2 speed Thanks guys I see my mistake. I'll switch them wire first thing tomorrow.
Not by much Kenh!