Will not Turn over

[dixon5553]

My 66 110 4 speed will not turn over - when I turn the key - nothing - no clicking, etc. I was going to try jumping the starter by connecting 12 volts from the battery to the purple lead terminal that goes to the started in the engine compartment to see what happens but need help in how to release the wiring connector to pull it apart - I don't want to damage this 58 yr old wiring -

Also a times after driving the car - I go to re start it and nothing happen (like now) but by letting it sit for 5 mins it will start again - like something needs to cool down or re-set. Any ideas.

What should I be checking to this no engine turn over - thanks in advance

RD

[RexJohnson]

You don't need to unhook the connecter just back probe it. I would maybe back probe from both sides. They should have the same results but if they don't you might have just found the problem.

[Frank DuVal]

You should check the HRPT aka The horrible red plastic thingy!

That is the red plastic nut mounted on the frame rail just in front of the battery. A 10 AWG or so wire comes from the positive battery cable to that screw and then goes to the connector for the body harness and the alternator. The screw gets rusty or the plastic looses tension on the screw and a loose connection is the result. Clean and tighten.

But first some troubleshooting. Do the headlights come on and stay reasonably bright when you turn the key and nothing happens? Or maybe the dome light, if no one is there to look at the headlamps for you. If the lights stay bright, then power is good up to the body harness. If the lights just dim slightly, then the solenoid is probably getting power, but is not pulling in (click). If the lights go real dim or out, then bad connection on battery terminal or HRPT or body harness to engine harness connector (maybe elsewhere, but these are easiest and most probable).

[bbodie52]

You may also want to unplug the large 12 pin multi-connector and examine all of the internal metal connectors to make sure none were damaged, melted or burned when you reversed the battery polarity.

There is a small two-wire connector near the firewall. The thicker wire (12 Gauge PPL) is the wire that actuates the starter solenoid when the ignition key is turned to the START position. The thinner wire has two wires that are spliced together. The 20 Gauge B/Y wire comes from the solenoid and provides 12V DC to the ignition coil while the engine is being cranked, to create a "hotter" spark to help the engine to start. The other wire that is spliced to the same connector is a special resistor wire that provides reduced voltage (6-7V DC) for normal engine operation after the engine starts. (The lower voltage provided when the key is in the ON position is desirable to extend the life of the ignition points by reducing the coil voltage to reduce arcing across the points as they open and close).

To test the starter and bypass the ignition switch, unplug the two wire connector that goes to the starter. Momentarily apply 12v DC from the positive battery terminal to the 12 Gauge PPL wire that goes to the starter through the engine sheet metal shroud. Applying voltage to the starter solenoid in this way should engage the starter and crank the engine. (This is the location where a remote starter switch, like the one below, would be connected to crank the engine from the engine compartment – desirable when performing some maintenance routines such as running a compression test on each cylinder).






Do you have a thick ground cable attached directly between the battery and the engine? The cable grounding the engine must be equal in wire gauge to the positive cable feeding the starter motor. Both battery terminal posts and the inside of each battery cable connector must be clean and tight for reliable, consistent operation.

Also check the battery voltage with a multimeter, or have the battery checked at an auto parts or repair shop that is equipped to test the battery. A faulty battery, or a battery with dirty terminals that can develop a high resistance between the terminal posts and the cable connectors can cause problems with intermittent starter action.

[jimbrandberg]

I just strip a little off the end of a wire and stick in next to the purple wire. I didn't know I was back probing and that sounds so much better.
Jim Brandberg
Isanti, MN
CorvairRepair.com

[dixon5553]

Frank - You are right, just the fact of me moving the wires around, it now starts. What does HRPT stand for? Is it just a screw that goes into the body that you tighten - metal or plastic screw?
What would cause the engine not to turn over when the car is being driven (hot engine) - and after sitting say 10 minutes it turns over like normal?
So just remove the two wires on the HRPT 0 inspect and clean as needed ?

Do you know any location that shows how to actually disconnect some of the wiring harness used on these cars - like the two wire harness (purple and yellow wires) that go to the starter.

And thanks to everyone that responded to you post so quickly,

RD

[Frank DuVal]

Google Packard 56 Connectors and you should see the tabs and corresponding "hooks" that you release by either pulling or slightly bending the hooks away from the tabs as you pull the connector apart.

[American Mel]

What does HRPT stand for? Is it just a screw that goes into the body that you tighten - metal or plastic screw?

RD

As stated above,
HRPT= Horrible Red Plastic Thingy (UN-Official name)
It is a red plastic lug that plugs into a hole in the frame.
The screw is metal, and expands the plug in place, while remaining insulated from the metal frame.
It is basically just a junction point for all of your positive wire feeds.
Over time it can become loosened and make poor connections.
HOT wires have reduced conduction.
Cooler wires conduct better.
That is why waiting will allow it to usually start.
Cleaning and tightening will usually be good for many years.

[dixon5553]

thanks Mel - this makes sense re the hot start issue - hope this is all that's effecting my car - appreciate the input.

RD