Stovebolt.com Forums The Shop Area The Electrical Bay 1965 230 12 volt no power to key

Went out to start the truck and upon turning the key no idiot lights no power to anything. Since the battery is 3 years old I figured I would start there. Pulled the cables off and cleaned up the connections using the proper tool. Still nothing at the switch. Hooked up the battery charger and put it on boost. Still nothing at the key. Disconnected the battery charger. Left the key on and jumped the terminals at the solenoid, cranked right over and started. Turned on the headlights and the engine immediately died. Original style Alternator. Volt meter shows no voltage at the big terminal (engine not running and key off). Next?

Sounds like you may have a fusible link burned out. Take your test light & start tracing.
George

Couldn’t work on it today the owner had prior commitments. It’s not his daily driver. Maybe tomorrow. Any idea the location of said fusible link?

The fusible link will be a short piece of wire between the battery cable terminal at the starter and the engine wiring harness. There might be two of them on some applications, one to the ignition switch and another to the fuse block or the headlight switch. Look for a couple of small diameter wires bolted onto the big battery cable terminal at the top of the starter solenoid. Tug on those wires a little- - -a burned fuse link will stretch like a rubber band and/or have blisters in the insulation from the wire inside burning. Then find the short that's downstream that caused the link to burn. They don't fail for no reason. I use a low amperage self-resetting circuit breaker like a 10 or 15 amp, spliced into the harness, for troubleshooting purposes.
Jerry

Thanks George and Jerry.

If the truck started with a jump across the solenoid with key on. it means the coil is getting power from the ignition switch. It means the ignition switch is getting power from the battery. No fusible link problem. It does not have a factory fusible link. One could have been added but don't think it is that. Solenoid not being triggered by ignition switch?

The wiring is, as you know: big cable from battery to starter. Smaller wire from battery to horn relay. Horn relay has a two screw terminal used for power distribution. Relay distributes, basically, direct power to ignition switch, headlight switch, fuse panel, alternator and voltage regulator. All RED wires. Some of the distribution goes thru fuses, connectors and terminal points. Check that distribution and all fuses.

IMPORTANT: Check to see that there is hot at the ignition switch battery terminal. If power there....Turn ignition to start. Ignition switch solenoid terminal (purple wire) should go hot. If it does not, it's a bad ignition sw. If it does, follow it thru the 6 pin connector and check it's continuity along the way to the solenoid "S".

Still trying to figure out why turning on lights kills motor. Large amp draw from lights is stealing power to coil? Ignition switch has weak ignition "ON" contact?

I assume no one has messed with ignition wiring or any wiring? Started one day and not the next. I assume static battery voltage is ≈12.6V and charging voltage at battery is ≈14V at high idle.

A dash volt meter is powered by switched power, so if key off, it would read zero voltage at it's battery terminal. If that's what
"the big terminal" means.

If you mean your multimeter voltmeter, I don't know what "the big terminal" means.

Martin, are you done horsenround yet?

Nope, the truck owner is overseas for a bit. Truck is locked up in his garage until he returns.

Truck owner called yesterday from the airport as he was boarding to fly home. Told me to meet him at his garage this morning at 9am central. Took my test light and multimeter along with my box of electrical tools/supplies. My first round of tests determined no power to the inside fuse box or through the fuses. The under side of the dash looks like a birds nest of multi colored wires. But my job was to get it starting again with the key. Knowing the fuse block gets its power from under the hood i took my test probe and moved there. Started looking for fusible links in the positive wires. I noticed a separate wire (mounded into the cable fitting) coming from the positive battery cable that had a fusible link in it. Yes bartamos it had a fusible link! I tested the link and it had power but upon following the wire I found it had come loose from a crimp connector near a relay on the radiator core support. Cut and cleaned both ends and did a proper splice and lo and behold the truck started right up and all the accessories worked. Since I had accomplished the job requested I packed up my stuff and had a long discussion with the truck’s owner about underdash fires caused by faulty wiring. He promised to add a rewire to his to do list. He’s happy, I’m happy, time to work on my stuff now.

The truck started with a jump across the solenoid, so the coil had power. So the ignition switch was supplying run power but not start power. A wire going to a relay? was loose. It was not a blown fusible link. At least that is what I read. Never-the-less, you did a very good and quick job for the person. Well done, sparky.