Electric Power Issues

[HEEP]

So, I have just finished doing the LS swap on the 1984 K10, and I am finding that I have more electrical issues than I was aware of. I had hoped that I had repaired all of the previous owner issues of wire nuts and twist and tapes.

At this point, nothing really works unless I turn on the lights. In other words, the radio doesn't come on until the lights are on. The dome light will not come on until the light switch is on, but the door jamb switches do work the light off when they close.

I am not sure where to even start at this point. nay ideas?

Thanks,
Bill

 

[Charlie]

 

[HEEP]

Thanks. Lots of info here, just not finding what I need at the moment.

 

[chengny]

So, I have just finished doing the LS swap on the 1984 K10, and I am finding that I have more electrical issues than I was aware of. I had hoped that I had repaired all of the previous owner issues of wire nuts and twist and tapes.

At this point, nothing really works unless I turn on the lights. In other words, the radio doesn't come on until the lights are on. The dome light will not come on until the light switch is on, but the door jamb switches do work the light off when they close.

I am not sure where to even start at this point. nay ideas?

Thanks,
Bill

At this point, nothing really works unless I turn on the lights. In other words, the radio doesn't come on until the lights are on. The dome light will not come on until the light switch is on, but the door jamb switches do work the light off when they close.

Is it only the radio and dome light that don't work until the lights are turned on - or are there other components that aren't working right?

When you say "until I turn on the lights", I assume you mean the headlights? What if the switch is pulled out halfway (i.e. only the parking/tail lights are activated) - same behavior?

Engine cranks over at normal speed?

 

[rpcraft]

Well, you are probably not going to like this answer, but if you have a rats nest under your dash the best thing to do is clean house and clean out the cut up wires and stuff. I good non-oem replacement harness can be found for under 250 bucks. Sure it won't be 100 percent factory or have a nice bulkhead plug on it like the 1000 dollar painless kit will, but mine was 180 bucks, has a setup for all the power and additional accessories that the OEM harness never had, and at the end of the day, its not going to burn my garbage down to the ground. I am not sure how wiring proficient you are, but sometimes it is actually easier to start over than being constantly broke down or aggravated with your ride.

 

[HEEP]

Thanks for the replies. Yes, I know that I really should have rewired the complete truck at this point. And probably will when I recover from this money pit. HAHA I just want to get it on the road for my son and make sure that everything works to a degree.

So a little update, after looking at the radio wiring and the harness in the truck, I realized that I read a wire in the schematic wrong. So I had wired the radio to get power from the lights, not realizing that I needed a constant hot that was not there in the original harness. So I got that fixed last night. Radio now comes on with the key switch.

Now, I need to understand the dome light and courtesy light and how they are supposed to work. Currently, the dome light works only when the key switch is on, not when you initially open the doors. Is this normal process? I guess I thought they should come on when the doors were opened. The door switches were replaced, and they do turn off the light when the door is closed, when the key is on.

Thanks in advance.

 

[rpcraft]

The dome light should be a constant power from the fuse box and not need the ignition switch on

 

[HEEP]

That is what I thought. I guess, that is the next set of wires to chase. Thanks....

 

[HEEP]

So, I was able to get the courtesy light under the dash to work. The PO had put a wrong bulb in it. So that works when the doors are open now and the jamb switches turn it off.

Tracked back the orange wire that is supposed to power the Dome light. it goes in behind the fuse block, but it does not have constant power, only switched. I guess, I may pull the fuse block out to see just what is going on behind it, as there is no telling what the PO did to this thing.

 

[Snoots]

You should be able to trace the courtesy light power to the dome light circuit. They are all switched by the door switches or the dash light switch.

 

[chengny]

That is what I thought. I guess, that is the next set of wires to chase. Thanks....

Something simple you might want to investigate before tearing into the harness/fuse block:

For some reason, there are two power feeds coming out of the fuse block that have the designation ORN 140.

One is hard wired and services the brake/hazard light circuits - via the 20 A STOP-HAZ fuse.

The other supplies power to the dome/cargo light circuits (and clock if installed) and isn't hard wired to the fuse block. It is connected to the block by one of those plug/socket arrangements. It is supposed to be plugged into one of the two sockets labeled BATT. Those two sockets are supplied by the 20 A HORN-DM fuse and should be hot at all times.

However in addition to the two correct sockets for the dome light power to plug into, there are five wrong sockets available in the block. All are ignition switched. Three are labeled IGN, one is labeled LPS and one PWR ACCY.

The sockets are all contoured differently so that only plugs intended for that particular mode of power supply will fit in the socket. But people can be very resourceful when they want to plug something in - even if it doesn't initially fit. Seriously, as I think you're discovering, it is not at all unusual to find all kinds of alterations made to the wiring harness (see far below).

This image shows the dome light power feed plugged in to the correct jack (yellow box). The red boxes show the other - incorrect - jacks:

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[HEEP]

So chengny, much appreciated on these pictures and information. I learned that the dome wire was connected to a switched port in the fuse block. I ended up removing the fuse block to be able to trace the routing of the wires, and found it. The next thing was the blower motor wires, not getting power through the switch.
During removing the fuse block, I found two wires that were heavily burnt and had been taped. Ended up pulling the terminal from the block, and replacing the terminal and ran new wire. Then finally figured out that the fuse terminal fir the fan motor had a bent terminal and the fuse not making a connection so a little bending and that is fixed.

So now, looks like the fuel gauge is not working. This thing is never ending.

 

[chengny]

So chengny, much appreciated on these pictures and information. I learned that the dome wire was connected to a switched port in the fuse block. I ended up removing the fuse block to be able to trace the routing of the wires, and found it. The next thing was the blower motor wires, not getting power through the switch.
During removing the fuse block, I found two wires that were heavily burnt and had been taped. Ended up pulling the terminal from the block, and replacing the terminal and ran new wire. Then finally figured out that the fuse terminal fir the fan motor had a bent terminal and the fuse not making a connection so a little bending and that is fixed.

So now, looks like the fuel gauge is not working. This thing is never ending.

Just another day in Square Body Paradise.

 

[HEEP]

Try another weekend in Square Body Paradise.
Well, we officially drove around the block today. Yes, there are still electrical issues. Right now, the fuel gauge doesn't work, temp gauge doesn't work, fixed the dome light, but don't touch the wire, as there is a break in it somewhere, so that will need to be repaired. But, we did drive it today. So the junkyard engine has a P0200 code, that shows open circuit in the injector system.
I'll be attacking them one by one to get them worked out.
Thanks for all the help.

 

[chengny]

Try another weekend in Square Body Paradise.
Well, we officially drove around the block today. Yes, there are still electrical issues. Right now, the fuel gauge doesn't work, temp gauge doesn't work, fixed the dome light, but don't touch the wire, as there is a break in it somewhere, so that will need to be repaired. But, we did drive it today. So the junkyard engine has a P0200 code, that shows open circuit in the injector system.
I'll be attacking them one by one to get them worked out.
Thanks for all the help.

You're welcome. Good luck.