Starting Problems *No power*

[vtwinvulcan]

Hello All, new to the forum here.  I have a 75 K10 that I am having some electrical problems with.  When attempting to start the starter makes one "click" and then there is no power going to anything in the truck (lights, windows, etc).  I have replaced one of the fusible links at the starter with no luck, still does the same thing, one "click" of the starter and then no power whatsoever.  The battery reads good and the starter is less than a year old.  I have checked all the fuses in the cab and they are all good too.  I plan to replace the other fusible link that is located by the firewall but was just wondering if there are other things that I could be looking at to be potentially causing the problem.  Thank You

[AZ4X4SQBDY]

So to be clear, you turn the ignition to crank the engine and instead of the starter motor turning you get a click from the starter solenoid then all the other electric function, dome lamp, instrument panel lamps, etc, go off and nothing.

Does the stuff come back on when you turn the key all the way off and it just repeats itself the next time you try to start it?

Off the top of my head, I would confirm the battery connections are clean and tight, then make sure the ground cable where it attaches to the engine is clean and tight. Physically unbolt them and confirm it's not arcing inside any of the connections. I would also connect a multimeter to the battery and watch it as somebody else tries to crank the engine. It's not uncommon to have a battery that checks ok with a meter at 12.5 volts and to drop to nothing when placed under load. 

[vtwinvulcan]

You are correct.  When attempting to crank the engine I just get a click from the solenoid and then all other electrical functions go off and nothing.  No power returns if I turn the key off and try again, the solenoid doesn't click then either.  I have checked all the ground connections to make sure they are tight, but I have not un-bolted them and cleaned them, I will do that.  I will also check the battery while placed under load.  Thank You for the ideas.

[bd]

... confirm the battery connections are clean and tight, then make sure the ground cable where it attaches to the engine is clean and tight. Physically unbolt them and confirm it's not arcing inside any of the connections. I would also connect a multimeter to the battery and watch it as somebody else tries to crank the engine. It's not uncommon to have a battery that checks ok with a meter at 12.5 volts and to drop to nothing when placed under load.

I agree, either a faulty battery or poor electrical connection(s).

[blazer74]

Been down that road and was the battery, but don't rule out the connections as well as the ignition switch.

[cl2sparky]

Check all terminals for corrosion. Can you start it at the starter solenoid?

Sent from my 1911-A1

[vtwinvulcan]

I have not attempted to start it at the solenoid, will try that next time I get a chance.

  Also this morning (Thursday) I went outside and the headlights/tail lights were on.  I had accidentally left them on on Sunday when working on the truck, however this was after attempting to start the truck and still getting the one "click" out of the solenoid and then no power.  So Sunday afternoon when I was done working on it I had left the lights in the on position but being there was no power to anything on the truck the light were not actually on.  Then 4 days later of the truck sitting and not being touched there is power again.  It's as if the battery had recharged over 4 days of inactivity.  So when I went outside this morning and turned the lights off I attempted to start the truck and the same thing happened, one "click" of the solenoid and then no power whatsoever to the truck.  Anyone ever encounter anything like this?  It was also pouring rain this morning, don't know if that could cause anything....

[Irish_Alley]

im going to guess the hot wire running to the starter. could be either end but sounds like the wire came loose and the click is all it took to lose what little connection it had

[bd]

Vtwinvulcan, read the posts.  The symptoms are indicative of "faulty battery or poor electrical connections" - emphasis on "poor connections."  So, Yes.  We have encountered this before.  Concentrate your efforts on loose and/or burned cable connections, frayed wires where they attach to their terminal ends, and damaged fusible links.

[vtwinvulcan]

bd, I have been reading the posts and they are very helpful.  When I asked if anyone has encountered this before I was referring the battery seemingly being dead and having no power but after four days of the truck sitting and not being touched power returns.

[Irish_Alley]

think about it like this when metal heats up it will bend. so the amount of amps you pulled to try and start it might have separated the connection. then i dont know why it took 4 days but the metal slowly went back and made the connection again.

[bd]

I'll try to help you understand what it appears is happening with your truck.  When a poor connection exists (unwanted excessive electrical resistance), voltage is consumed (used up) across the connection as it forces the flow of current through the added resistance.  The result is electrical power is converted to and wasted as heat at the poor connection.  Arcing often results.  The heat produced further degrades the connection and so on.  As the connection cools, it will sometimes reestablish sufficient continuity to pass a low current flow (lights and buzzer, etc).  But, demand a high current flow, such as cranking the engine, and the connection arcs and opens again.  Eventually, resistance through the connection degrades to the point that it won't reestablish the connection and a "hard failure" occurs.  Hard failures make diagnoses easier, because they are not dynamic - the failure remains fixed and constant rather than intermittent. 

The poor connection that causes the symptoms can occur nearly anywhere in the power bus, including inside the battery.  Finding an intermittent failure requires patients and systematic observation, being very careful to avoid assumptions.  So, thoroughly inspect all the wiring connections and fusible links that supply power from the battery into the cab and the ignition switch.  If any connections are loose, disassemble them and check for evidence of heat stress and arcing then burnish and reassemble.  Inspect the fusible links for evidence of heat stress and discoloration at the terminations.  Replace them with the appropriate gauge link if suspect.  For a technical description of how to determine the correct gauge and make a fusible link, see How to make a Fusible Link in our Technical Pages.

Does this help?

[vtwinvulcan]

Yes, your explanation helps greatly!  Thank You.