Hello all. I have a 1979 k5 with the sm465/350 combo. I'm not sure if it was this configuration stock. I'm working on the body but want to take a break from metal work, and try to get this thing running. I have no idea where to start. There is aftermarket switches all over this thing and nothing works. When I turn the key on nothing happens. There is a junction block on the firewall with 5 wires comming off one side, and nothing on the other side. I can turn the ignition switch with no key in it. There's no spark with ignition in on position and power jumped direct to the starter. I have no idea where to start on this thing! Electrical is my downfall. I'm hoping someone is an electrical genius and can walk me through where to start. Any help would be greatly appreciated!!
CK5
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1979 k5 electrical nightmare
- Thread starter Stevenf90
- Start date
Basic questions.
How much do you want to end up spending?
Is this a forever truck for you?
What are your end goals for the truck?
I ask because if you plan to make this better than new and drive it forever. Then it will cost but it will be a vehicle you know and trust. With that in mind a complete aftermarket wiring system might be your easiest and fastest method. However, while you are doing that. Then maybe a tilt column is wanted, the XJ steering shaft swap would be a great driving modification to make. See how things are snow balling and getting expensive?
But if all you want is to make it start, move and load onto a new buyers trailer. Find the biggest red wire in the engine bay that gets power when you turn the key on. Plug it or make a plug to plug it into the distributor, fire it up and call it done.
How much do you want to end up spending?
Is this a forever truck for you?
What are your end goals for the truck?
I ask because if you plan to make this better than new and drive it forever. Then it will cost but it will be a vehicle you know and trust. With that in mind a complete aftermarket wiring system might be your easiest and fastest method. However, while you are doing that. Then maybe a tilt column is wanted, the XJ steering shaft swap would be a great driving modification to make. See how things are snow balling and getting expensive?
But if all you want is to make it start, move and load onto a new buyers trailer. Find the biggest red wire in the engine bay that gets power when you turn the key on. Plug it or make a plug to plug it into the distributor, fire it up and call it done.
I'd like to beable to get the floors/body done and drive it, but it's not going to be a complete restoration or mint condition truck. I put a positive wire from the battery to to junction block on the fire wall and got power to the lights now when I turn the ignition on. I also found a wire unplugged from the distributor. Once I plugged it in, I have spark now. I don't have fuel comming from the mechanical pump into the fuel lines, but I dumped a bit of gas into the carb and got it to fire for a second. So that's great news. My main issue now is that it won't crank or do anything from the ignition switch. I have to turn the ignition on, and then jump power from the positive terminal on the battery direct to the starter via jumper wire. I'm not sure how the ignition/starter should be wired together.
Look for a red wire with a fuse link down at the starter. That wire should power up the ignition switch. The wire should be attached to the large post of the starter along with the positive battery cable.
Off the starter, I got the main positive cable that runs up to the battery off the big lug on the starter. On the smaller lug, there's a small red wire that is zip tied to the main battery positive cable . This also runs up to the battery but is loose/not conmected at the battery. This is what I have been using to jump start it, by touching the small red wire to the positive post on the battery. I also just noticed my main fuel line is leaking at the fuel tank from dry rot/cracking. I will have to run into town tomorrow and buy some fuel line, and hopefully get fuel up to the carb.
Alright, so I couldn't wait to go get the fuel line so I went in tonight. I replaced the lines that were rotted and it starts up great jumping it from the battery to the starter... I now have to figure out the wiring from the ignition to the starter. Would there be anyone who has wiring schematics for the ignition down to the starter? It was mentioned there should be a red wire from the starter to ignition? I don't have that... just the big battery positive to the starter and a small red wire from the starter up to a dead end which I use to start the truck... it turns off when I turn the key off, but it won't start with the key
The terminal block on the firewall: is there power on one side? Or neither ? It sure appears the ignition switch failed, and somebody choose to use swithes rather than replace the ignition switch. You may want to get the key cylinder and the ign switch and just replace both while your in the column.
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On the terminal block on the firewall, there is 5 wires coming off one side, the other side didn't have anything. I did some digging and found the side with nothing is supposed to have battery power. I have now put a wire from the battery to the empty side of the terminal block on the firewall. I now have power with the key on. I replaced some leaky fuel lines off the tank, and I can now get it to fire up and run by having the key in the on position, and jumping the starter with a wire from the starter , direct to the battery.. I can not get it to start with the key from the ignition switch... it was mentioned earlier that there should be a red wire from the starter with a fuseable link, however I don't see that. I think there is a wiring missing from the starter to the ignition switch possibly?? The rest of the wiring is pretty hacked up looking... lots of cut wires at the fuse block and a mess behind the dash.
the little red wire you are using to jumper the starter solenoid is someones hackery. The small "S" terminal on the solenoid should have a 12g purple wire that comes through the fire wall bulkhead connector, to the clutch safety switch (79 may not have had this), and finally the ignition switch. Clutch switch will be a 12ga purlpe and 12ga yellow wire in a single connector, under the dash near the clutch pedal, may be jumpered together
the wire @500$k5 is talking about is fuse link. This should be a 10ga red wire, that has a short section of brown?, wire at the starter. The fuse link wire feeds power to the junction block on the fire wall, the battery powered circuits in the fuse block, the head lamp switch, horn relay, alternator, and lastly the ignition switch. The Ignition switch should have 2 battery hot wires.
the wire @500$k5 is talking about is fuse link. This should be a 10ga red wire, that has a short section of brown?, wire at the starter. The fuse link wire feeds power to the junction block on the fire wall, the battery powered circuits in the fuse block, the head lamp switch, horn relay, alternator, and lastly the ignition switch. The Ignition switch should have 2 battery hot wires.
Yes this thing must be hacked up pretty good... I don't have any purple wires near the starter I'm not sure what the "s" terminal is. Is that the small lug on the starter(the one my small jumper wire is connected)? I see the clutch switch under the dash. The clutch switch has two, two prong terminals coming off it. One is empty, the other has a connector plugged into it with one orange and one white wire. The orange and white wires(plugged into the clutch switch) go around to the fuse block and I can't see them come out the firewall side of the fuse block... I do however see the 2 prong connector your talking about with one yellow and one purple wire. This connector(yellow/purple wires) is just zip tied to the steering column not plugged into the clutch switch. Should I plug this into the other 2 prongs on the clutch switch? I could plug it in, but it doesn't have the proper connector which would lock onto the clutch switch, it is a different connector than the other orange/white terminal currently plugged into the clutch switch.
Also, I just put a wire direct from the battery to the junction block on the firewall. It seems like your saying that that power wire needs to come from the starter and not direct from the battery, correct? If so, could I take the red wire that I'm using to jump the starter and use that to wire up to the junction block? Instead of using that one to jump at the positive battery terminal to start the truck, I could connect it to the junction block and remove the wire I put in from battery positive to the junction block(on firewall) ?
yes the the purple wire to solenoid goes to the same terminal the red jumper wire you are using to activate the solenoid. Putting the small red wire you use to activate the solenoid to the bus bar/junction block will not help. You can power the bus bar/junction block from the battery, as long as you have some kind of fuse near the battery end of the supply wire.
well i am not sure now that I have the wire colors correct for clutch safety switch. In another post here someone else said those wires were orange and white, even thou the correct year wiring schematic showed purple and yellow. I leave for now esp since the plug doesn't match.
well i am not sure now that I have the wire colors correct for clutch safety switch. In another post here someone else said those wires were orange and white, even thou the correct year wiring schematic showed purple and yellow. I leave for now esp since the plug doesn't match.
Wes harden I've been messing around a bit and on the yellow/purple connector that you mentioned(currently not plugged into anything), when I turn the key, the yellow wire gets power from the ignition in the start position, I followed the purple wire out to the engine bay side of the firewall and that wire has been cut off and is just hanging there... no power to when I turn the key to the purple side, BUT, I jumped the yellow side to the purple side with a jumper wire and with the key turned, it gets power to the cut off purple wire inside the engine bay... so now do I just have to get some 12ga wire and connect that purple wire down to the s terminal on the starter? If so, I will go into town and get some wire tomorrow... It seems(I think) that with the purple wire extended and connected to the s terminal on the starter, the yellow wire would send power over to the purple with the key turned to the start position? I can try and plug it into the neutral safety switch and do this tomorrow... but is there any idea what the orange/white wires are that are currently connected to the neutral safety switch? There is two, two terminal plugs on the safety switch, do both the yellow/orange and purple/yellow need to be plugged into this at the same time?
See my above post^^ I think you are correct with the yellow/purple.. but I do also have orange and white wires plugged into the safety switch... the purple/yellow are there and the yellow gets power with the key in the run position , however the yellow/purple are not plugged into the safety switch... it's just zip tied up to the steering column, open.
YES!! So I cut the zip tie holding the yellow/purple wires to the steering column and plugged it into the safety switch. I stripped off a piece of the cut off purple wire at the fuse box inside the engine bay, then I just used a piece of random wire I had to connect the cut off purple wire at the fuse box, to the wire I was using to jump start the truck and it now starts with the key!! Thanks a bunch man.. only thing is, is that I didn't have to push the clutch in for it to start... so the safety switch isn't really doing anything? I also have about 6 more wires just cutting off at the fuse box inside the engine bay I'll have to figure out.. *sigh*
That small red wire would go to the neutral safety switch if you had one, but otherwise?may go through a clutch swith? Before going to the ign switch.
Signals issues are from a bad ground.
Go over all you grounds and get a good contact on the metal
Sorry. I was out of town this weekend and failed to follow the post. Good job everyone,on getting the yellow/purple hooked up, and getting it starting!!
