This was badly accessory wired to pull a trailer, attached to the gas pedal is a contact with a square block about 4 inches long that moves out towards the driver when the pedal is pushed. It has two terminals lugs, there are no wires. It looks to be an add on but I have nothing to compare it with, what it does is what it is for. Having removed the instrument panel to replace the circuit board, the two wires for the tach are there, red and black at the plug but the red one is hanging and goes nowhere. The truck has a MSD 6A ignition, don't know if the two are related as far as wiring. The wiring diagrams help with everything that is original but I have no info on the additions or changes. Need some advice because I really want to be driving this instead of using it to hold the garage floor down. Pics of throttle, tach plug, and termination of red tach wire. Thanks!
I assume you are just fixing old wiring and not installing a new harness so...... I really don't know what you what to know and I don't understand why you are messing with silly pedal wiring and trailer wiring? REMOVE everything that is not original and use the diagram to wire/rewire the truck. We can't answer questions about unknown, very old, add on trailer brake wiring and etc. It's junk. Remove. As far as the tach wiring. Do you actually have an optional stock tach? Post a link to the diagram you are using and I will help further.
What about this comment? seems you already cleaned it all out and were OK???????????? weeks ago??????
"Thanks for all the advice everyone. Believe I have all the extras out, Properly soldered and shrink wrapped the obvious bits together. Since it is all accessible the next step will be to inspect every wire for anything missed it nicked, check grounds, continuity check, and hit the power. Fingers crossed... Once again, Thanks!"
Well B, I thought I was done until I pulled the instrument panel and found all the light switch splices, terminals, and relays stuck up under the dash and tucked on top of the AC duct. Couldn't see them before. Three of the circuit board connections were burned clear through. So taking your plan B advise a new harness has been ordered.
1. Do you have a factory tach? 2. Do you have HEI or points? 3. What is the vendor and part number of the wiring harness you ordered. 4. I didn't indicate you needed a new harness, just didn't know..
The boys are right. It is a Kick down switch. You said it was for the trailer. The switch was mounted there or near the carb, depending.
If you still have the 400, you DO NEED that switch. I have read all of your posts and never saw that you said what trans the 71 has. The switch was not wired, you said, so maybe the trans was changed or someone was in the process of rewire. That switch is still available.
Appreciate it. I did finally figure out that was the kick down switch. Confirmed it is a 400. I can eventually figure our just about anything.....Have always, "done for myself" but this is my first with this sort of project. Literally a beach ball size bundle of excess wiring and components, changing color and size wires. Scotch lock, twist n tape, and dead ends. Spending half a day internet searching info gets a million responses but rarely what you are specifically looking for. My former garage mates, 78 GMC K15 Sierra Grande stepside, 81 K10 stepside, and 85 K10 Silverado were all bought new. That was a long time ago...
Kick down had terminals on it the wires had been cut and gone. From what I have figured, at least for this bit is it needs a wire from the ign terminal on the fuse block to the kick down then from the second of terminal to the lug on the trans. The spedo cable has a roundish switch on a foot long extension to the cable mount. There is a two wire pig table on that, black and white..that I believe the white wire from kd plugs into and then the black is actually what goes to the trans lug. Scrappy pics of the item speaking of...
Not being an expert. There is, was so much garbage it has been difficult to figure out what is and isn't dealer or after market add on. Already trashed 2/3rds of it. This is the remainder of the pile...
Hy mac67 and guys that devise in the middle of the speedo cable is a generator, they are used to generate voltage that an electric speedometer converts to miles per hour. The speedo's have multiple switches which have to be set in certain ways depending on your final drive ratio and tire size, hope that helps.
That most certainly does help, and explains why the cable was disconnected at the head behind the instrument cluster. It is soon to be dispatched to the spark parts bin. The last remnant of, "say what"! Tidy up and finally reassembly shall commence....
So the harness is on back order. In the mean time if you guys don't mind.... There are no wires from or to the two term stop light switch, no plug from the harness end either. 69-72 diagrams have conflicting info. One says hot from fuseblock, others have hot from headlight switch or inst cluster. Not entirely sure which wire at the harness will get this into the brake light system. Hot from fuse block makes more sense. Sorry about pestering everyone with this. Tend to over think things and I sure it is simple but there is so much conflicting info... Wish I still had the Chilton shop manuals from the station... Going with white to the Directional signal connector at the column and orange to interior dome light connection, unless told no.
Update....with one exception, everything is back and we have life. When I connect the neg at the battery the passenger side turn signal flashes continually. Signal switch position makes no difference. Powered obviously but no changes to the signal switch or instrument panel wiring. Swapped out flasher unit, made no difference. Hazards work on all four corners, left is dead when switched on...followed the wires and did not find anything weird. There is a loose, inch long brass spring that was taken out from under the signal switch. Looks like out if a pen.... Signals did work before. Appreciate everyone's tolerance for all this, Stovebolt mentors.
Last edited by mac67; 08/25/20202:12 AM. Reason: Additional info
One of the signal switch contact springs was out of the nest. Put a new carbon contact in the spring, found the horn contact in the column. That took care of the signal Flashing continually. Brake light and downshift switch is connected properly and it all functions...human y'all!
