WTF, no power with ign in run position

[85 Jimmy]

With the key on I have no power, but when I turn to start I have power. This is a problem b/c as everyone knows, it won't stay running...

Alittle background, I swapped the truck over to TPI using a street and performance wiring harness and the corvette ECM (can't remember the number off the top of my head). The motor was running fine , I just swapped in a Dana 60 front and on my test drive I shorted out the battery and burned up a fusible link. I replaced the fusible link today and now I have no power with the key in the run position. I checked every other fuse that I can find and they are all good.

 

[diesel4me]

Which fusible link blew??..there is more than one,usually two are in thick red wires at the starter solenoid terminal the battery cable goes too,and another up on the firewall near that junction block thing next to the brake booster...some have one between the altenator output post and the wire that goes from there to the fuse box..

Seeing you have an aftermarket harness,my advice might mean nothing,if its not set up like the original harness was...but I would think it wouldn't be much different...might have the fuse links in different places??..

 

[Fordum]

When you say you have power with it in start, do you mean that it tries to start, but dies when you go back to run, or that everything that is supposed to come in in ign only comes on in the start position.
Radio, fan, things like that.

If so, then you either have a seriously screwed up ignition switch, or most likely you have somehow swapped the start wire and the ignition wire.

Most setups turn everything on when its in ignition, but turn it all off when you go to start it.
That is so that no voltage spikes get to the electronics, and so that the starter gets all the juice.

However, if it does not try to crank when you turn it to accessory, then its most likely its a bad ignition switch, or one that is loose somehow and the rod is not pushing it all the way.

 

[85 Jimmy]

Which fusible link blew??..there is more than one,usually two are in thick red wires at the starter solenoid terminal the battery cable goes too,and another up on the firewall near that junction block thing next to the brake booster...some have one between the altenator output post and the wire that goes from there to the fuse box..

Seeing you have an aftermarket harness,my advice might mean nothing,if its not set up like the original harness was...but I would think it wouldn't be much different...might have the fuse links in different places??..

The link that goes to both posts of the junction block that splits off with one wire going to the alternator and the other going to the fuse block.

 

[85 Jimmy]

When you say you have power with it in start, do you mean that it tries to start, but dies when you go back to run, or that everything that is supposed to come in in ign only comes on in the start position.
Radio, fan, things like that.

If so, then you either have a seriously screwed up ignition switch, or most likely you have somehow swapped the start wire and the ignition wire.

Most setups turn everything on when its in ignition, but turn it all off when you go to start it.
That is so that no voltage spikes get to the electronics, and so that the starter gets all the juice.

However, if it does not try to crank when you turn it to accessory, then its most likely its a bad ignition switch, or one that is loose somehow and the rod is not pushing it all the way.

Nothing turns on when the key is in the run position, then when I turn to start, right before the starter kicks over everything that's supposed to turn on (fuel pump, electric fan, etc) will turn on, and as long as I hold the key over the truck will run, then as soon as I let off it dies. When I replaced the fusible link I just cut out the old one and put the new one in the same place.

 

[Fordum]

Not sure this will work. I cropped the picture so that I could enlarge this part, hope it works.
the vertical lines with the little arrows are the switch parts.
The switch is shown in the locked position.
If you go to accessory, the little arrows move down to the bottom circles.

All the arrows move at the same time and make contact with the circles at the different positions.
The three left hand sets are all hooked to the battery and put power to the circles as they touch.

Note the one labeled ign1. it is the only one that covers two positions.
The battery is hooked to it in both the ignition and the start positions.

I think the bottom part of the contacts are bad on your ignition switch.
When it goes to ignition, it does not make contact. But, as it moves on up, towards start, then it touches a good part and puts power to the ign1.

Well, fart. Unless you have been having problems with that switch, you should ignore all that, because I am an idiot.

Its been a long day, and I'm hurting so I am not firing on all cylinders.

Odds are that you still have a blown fuse link. When you put power to the starter, it is backfeeding the dead link.
Note on that schematic there are more than one battery hookup. One of them is dead and it gets powered up when you go to start........

I will post another schematic too, and notice all the fusible links, one of which comes from the battery.

 

[lectric80]

Nothing turns on when the key is in the run position, then when I turn to start, right before the starter kicks over everything that's supposed to turn on (fuel pump, electric fan, etc) will turn on, and as long as I hold the key over the truck will run, then as soon as I let off it dies. When I replaced the fusible link I just cut out the old one and put the new one in the same place.

That information points to the rod or the ignition switch itself. If everything is coming like normal, but right before the starter spins, the switch is most likely suspect. Either a contact moved, or is worn to the point that it just barely catches at the end of the throw.

It is also possible there is another fusible link down by the starter that failed as well. I would check there first, but I am almost betting that it is going to be a switch problem.

 

[85 Jimmy]

Well I was out testing stuff with my test light and my fuses don't have any power, so I put my clamp on a power and was testing my fuses to see if they were grounded out. The ign, ga/idle, dir/bu, and inst fuses are grounded out. When I was doing that I had the alternator unplugged cause the brown wire is grounded out while it's plugged in, when it's plugged in the aux heater, htr/ac, and power windows are grounded out. Also when I pull the ga/idle fuse a buzzer under the dash goes off until I put the fuse back in.

I'd like to fix this problem, but this might just be my excuse to swap my body for the 91 blazer I have and scrap this one so my wife stops bothering me about having a parts truck...

 

[lectric80]

Check the wiring around the starter, my guess is there is another fusible link that is toast.