The Stovebolt Site Forums The Shop Area The Electrical Bay Darn thing won't start

Okay, so this morning, I go to start the truck, and I got nothing. Tester says the battery is fully charged. This is on the 66 C10 by the way.

At any rate, turn the key and there is nothing. Gauge shows a draw on the battery when you turn the key, and all other electrical works - just nothing - not a sound when turning the key.

So, a bunch of my buddies were telling me check this, check that - whatever. We tried pushing it down the hill to pop the clutch and start it. All that did was lock up the wheels (like I slammed on the brakes). I think that was my fault because like an idiot, I had it in granny when I popped the clutch at about 15 mph.

Any ideas where to start this quest? Would I have had better results if I were in a higher gear?

Had the truck out on the road two weeks ago with no issues. This was totally unexpected.

I know with my motorcycle, 2nd gear is a must if you're going to try and pop the clutch.

As far as the electrical issue, I'd start with the starter wires to make sure you're not grounded out somewhere. That's about the extent of my electrical knowledge.

3rd. gear on the granny geared 4-speed is the way to go for bump-starting. Also try tapping on the starter housing with a hammer while someone holds the key in the start position. You've probably got some badly worn starter brushes that are preventing the pull-in winding on the solenoid from getting a good ground.
Jerry

One thing you could try is to jump the solenoid with a screwdriver or wire lead. Sounds like your key switch is not supplying power to the solenoid. You could also check that by using a VOM and see if you are getting power to the solenoid when you turn the key to start. If you are getting power, then either your solenoid is burned out, or there is a ground problem as Jerry suggested.

Kurt

There are two solenoid windings, a pull-in and a hold-in winding. The pull in grounds itself through the starter brushes, and the problem with poor brush contact has existed since the design was pioneered by Delco in the 1940's. I've seen dozens of solenoids changed over bad brushes, with no improvement in starting performance whatsoever.
Jerry

Well, let me add this to the symptoms, as I forgot about this little anomaly. When it first wouldn't start, I hooked the battery charger up to it with the battery still in the truck. The charger came on before I plugged it into the wall. Never saw anything like that before.

Here is the update. The problem all along was a bad battery - go figure. I was reading through some troubleshooting tips on a different post, and decided to try some of the tips. Everything pointed to a bad battery. Found a loose connection on the positive terminal. So, I replaced that, put in the battery out of my other truck and she started right up.

Still think the alternator might be part of the problem. Headlights seem pretty dim until I hit the gas.

The brightness of the headlights is a very poor indicator of charging system performance. That's what voltmeters and ammeters are for. An alternator that's doing its job right will produce a battery terminal voltage above 13 volts at idle, rising to 14.5 volts or more when it's running against a fully-charged battery at cruise speed. The condition and state of charge of the battery, not the alternator or generator, determines the operating voltage. Be sure the battery is fully charged and in good condition before blaming any other component for poor performance!
Jerry

Good to know. Thanks

Alternator has an open diode. Throwing way too much at the battery.

Open or shorted diodes affect the charging current- - - -not the voltage. The classic symptoms of diode problems are very noisy operation and a maximum amperage output of less than 1/3 of the rated capacity. A 65-amp alternator with a bad diode will produce maybe 10-12 amps max.

If the voltage output is too high, the problem is with the regulator, not the rectifier diodes.
Jerry