Author Topic: No Power to Switch  (Read 1392 times)

Offline Rcf

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No Power to Switch
« on: October 07, 2021, 06:18:08 PM »

It seemed strange to me that I started by '83 K30 and backed it out of the garage to raise the bed in order to work on the wiring to the rear lights.  With the 4-way flashers working I was looking for the wires in use.  Couldn't find any, I went to the cab and discovered the 4-ways weren't working.  Too hot I guess.  To replace the flasher, it was easier to remove the plug-in wire directly below the flasher space.  After replacing the flasher and plugging in the wire I removed, I tried the flashers.  Nothing.  Then I turned to switch to ON to try the turn signals and had no power - the alternator light did not light.  Had headlights and horn, but nothing else.  It got dark and I had to quit.  Do you all have any ideas?

Offline Rcf

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Re: No Power to Switch
« Reply #1 on: October 09, 2021, 09:34:23 AM »

Well, for an update.  On another issue sometime back, a knowledgeable member called "bd" gave me some insight about troubleshooting wiring issues.  I followed what he said to the point where it seemed the switch was the culprit.  So, I went to work getting access to the switch.  I had the steering wheel lowered onto the seat where I could get to the switch; and, for some reason, I reached over and turned the key on.  When I did, there was power.  While I was happy there was power, it is troubling not to know why I didn't have it before.

Anyway, I got everything put back together and there is still power.  And I found a broken wire to the right rear brake light, which started this whole thing.

Offline Rcf

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Re: No Power to Switch
« Reply #2 on: October 30, 2021, 02:32:16 PM »


So, this story gets better.  After doing some work on the truck, I tried to start it.  No Power.  Actually, that was good.  I thought the switch could be bad, and this way it is still in the garage and not out somewhere stranded.

Anyway, I installed a new switch.  It worked fine.  Got that behind me and it shouldn't leave me stranded somewhere - - I thought.  This morning I  was checking out the plow lights and I turned the switch to ON in order to test turn signals only to find no power.  Still had lights, but nothing through the switch.  I know the switch is new and the plugs are secure.  Any ideas on what else may be wrong?  Would appreciate any insight.  Thanks.

Online bd

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Re: No Power to Switch
« Reply #3 on: October 30, 2021, 03:16:37 PM »
The factory wiring manual is your friend:  1983 Wiring Manual

Begin by giving the fusible links at the starter solenoid and the firewall junction block a firm tug.  If any of the fusible links stretch or separate, replace them according to How to make a Fusible Link.  At the same time, make sure the fusible links show no signs of heat damage and that the studs to which they are connected are suitably tight.  Next, when the symptoms occur, using an incandescent test light clipped to a good clean ground, switch the ignition ON and probe both sides of every fuse and every power tap in the fusebox (do not move or disturb any wiring under the dash as you perform this step).  Record exactly what is and what is not hot (12 volts) and post the results.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Rcf

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Re: No Power to Switch
« Reply #4 on: October 30, 2021, 06:36:43 PM »

Thank you, bd, for your input and direction.  For me, perhaps one of the biggest obstacles will be what a fusible link is.  I have examined most of the wiring on this truck; except, of course, for a lot of the under-dash wiring that is largely hidden from view.  Fuses in the fuse panel are a different matter entirely.

From the manual there are two wires bringing power to the switch.  The best I can tell terminals BAT 2 and BAT3 receive power.  Wire 3 Red 2E (2E) is connected to BAT 2 and wire 3 Red 2C (2C) is connected to BAT 3.  Both 2E and 2C originated at a splice of wires 3 Red 2B (2B) and 3 Red 2A (2A).  2B terminates at the fuse block at STOP HAZ.  2A terminates (or actually originates) at the firewall bulkhead connector at location 2.  Location 2 changes to 2E on the other side of the firewall.

Based on all of this, it would seem:
1- Power comes from the battery through 2A
2- 2A splices with 2B, 2C and 2E
3- 2B goes to the fuse block
4- 2C goes to the switch at BAT 2
5- 2E goes to the switch at BAT 3

I am going to do some circuit testing and let you know what I find.  I really am at a loss about fusible links.  Even though I am quite a novice, I do know they are to protect over current.  The issue for me is that I have not found any on this 1983 K30.  We cannot overlook the possibility that I am not aware of what I am looking at. 

Online bd

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Re: No Power to Switch
« Reply #5 on: October 30, 2021, 07:43:11 PM »
Read up on fusible links in the thread previously linked and Fuses and Circuit Protection.

Look at the attached images below for two relevant examples.

The fusible links are the 6" long wire extensions between the urethane insulated splices and the respective power sources - in the attached images the power sources are the 3/8" starter solenoid stud and the firewall junction block stud, respectively.  Fusible links are ALWAYS inserted at the "hot" end of power feed wires.  This way the entire length of wire is protected.  Fusible links are ALWAYS sized four wire gauges smaller than the wires they protect (see the tables in the linked threads).  With very rare exception, fusible links are ALWAYS 6" long.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Rcf

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Re: No Power to Switch
« Reply #6 on: October 30, 2021, 08:18:19 PM »


Thank you for the pictures bd, a visual is always better.  But, even though now I know what one looks like, I am more certain my truck doesn't have any.

Sometime ago, you labeled wires for me on a picture of the firewall bulkhead connector I posted at your request.  I tested the wire you marked 2E and found no power.  That wire runs to the firewall junction block, like the one in your picture showing the fusible link.  Other than there isn't any fusible link on my junction block, I tested the stud and got power.  I, then, tested the terminal ring at the stud and got nothing.  What in the world?  How could it be so corroded?  Well, it wasn't corroded.  It also wasn't tight.  After the nut was tightened, I got power.  I'll have to doctor it up a bit more.

A week or so ago I lost power and started to look at the ignition switch.  When I dropped the steering wheel to get to the switch, I must have jostled the wire as I loosened the nuts on the steering column at the firewall.  When I turned the key, I had power and didn't know why.  The same thing may have happened yesterday when I replaced the switch.

There's a lesson to be learned here.  I hope I learn it before I go broke buying parts I may not need.

Anyway, thank you for sharing your knowledge and insight.  It is very valuable to me.

Online bd

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Re: No Power to Switch
« Reply #7 on: October 30, 2021, 11:58:38 PM »
Missing fusible links is a serious situation!!

The fusible links (or suitable substitutes) are essential to protect your vehicle's electrical system from fire and your truck from burning to the ground!  This is no joke!  You need to figure out exactly how power is introduced into the wiring from the battery - whether the wiring has been grossly altered or whether a PO simply cut out the OEM fusible links because they too were experiencing electrical problems and foolishly hacked the wiring out of stupidity.  Reintegrating the fusible links is essential and should be your number one priority.  Take this advice to heart while you still have a truck to diagnose!  Until the fusible links are effectively installed, I would disconnect the battery ground cable except during those specific times that you need battery power for your diagnoses.

This may sound daunting at first, but a focused effort should come to fruition in an uninterrupted afternoon.  While diagnosing, connect power to the vehicle through a 30-amp auto-reset circuit breaker outfitted with 18" long 12-gauge leads and heavy-duty alligator clips.  Be sure to tape bare terminals to prevent inadvertent arcing.  Insert the circuit breaker between the battery positive post and the battery positive cable.  This will provide temporary protection until the fusible links are in place.  If the circuit breaker begins to trip and cycle OFF-ON-OFF-ON-OFF-ON... you can disconnect it from the battery until you sort out why.

If you are fortunate, the process will be as simple as installing new links to replace those removed by the PO, thereby, restoring the wiring to the factory configuration.  At worst you will need to string some new wire.  Nonetheless, the project should require no more than a weekend as long as you have alternate transportation for parts runs.

Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Rcf

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Re: No Power to Switch
« Reply #8 on: October 31, 2021, 03:26:12 PM »

Certainly sounds like a serious issue.  I'll be looking into them.  Thanks.