[malibuman66]

Morning

I have a bit of a dilema with my ignition system, here goes. Recently I went to turn my get to start the car and nothing happened. So I waited awhile and still nothing. So replaced my neutral safety switch and then car started. Few days later same problem , no start. So ran test from battery positive to starter ignition side with key on and starter engaged telling me starter is ok. So problem lies in ignition switch, replaced ignition switch and problem seemed to go away. Started everyday with no problem. Yesterday after I finally got my kickdown cable in the car and back together , I went to start car turned over fine, didnt start due to lack of fuel, so pumped gas and went to start again, nada, nothing, like dead, like no battery in car. So was about to run same test again but went up for dinner came back down and said to my better half watch it start now and damn if it didn't and not only once but about 8-10 times over again with no problem. Confusing as hell this car is , feels like its possessed. Told my wife I was going to have the blessed !!

So my question is since I replaced the ignition switch is it possible that I could have a faulty switch again, the neutral safety is new, the starter is only 6 moths old , new wiring harness, new voltage regulator, actually all new electrical and mechanical components in the engine compartment.

[docvette]

[color=yellow][size=3]Doc Here


What kind of Car are we dealing with here?

What Engine?

Carbed or EFI or TBI?

Electric or Mechanical Fuel pump?

little more detail is needed to make a good guess...


Doc [/size][/color]

[horvath]

Have you inspected ALL the related wire-connections??? Sounds like there could be a lose wire or a frayed wire; sometimes connecting, sometimes (after getting bumped) not.

Alan
54 Chevy Pickup

[malibuman66]

Originally posted by docvette
[color=yellow][size=3]Doc Here


What kind of Car are we dealing with here?

What Engine?

Carbed or EFI or TBI?

Electric or Mechanical Fuel pump?

little more detail is needed to make a good guess...


Doc [/size][/color]

Doc

66 Chevelle malibu
350 cubin inch stock
650 Holley Carb
Stock Distributor
Mechanical Fuel Pump

Thanks.......John

[66Caprice]

I would check the engine wire harness connection to the fusebox at the firewall. Since you changed the engine harness, maybe one of the connections on the firewall to the fusebox got bent and is not contacting all the time (This happened to me). If it's the original fusebox, make sure that connector is on all the way too. A slight change in temperature can cause a bad contact to go on/off intermittently.

Probably the best troubleshooting to do is catch it when it either wont crank or will crank but not start, leave the ignition switch where it is, then check for voltage.

On the ignition switch, the red wire should have 12v all the time, the purple wire should have 12v during crank and the pink wire should have 12v during run.

[docvette]

[color=lightblue][size=3]Doc here

Thanks for the info...

The place to look:
(since the Church Doesn't Exorcise inanimate objects anymore...)

Check the Solenoid on the Starter, Be sure it is Tight on the Starter, and the Cables are Secure to it. The 10 Gauge Red wire on the main terminal with the Battery cable can turn the system off if it is loose, so be sure it's tight.

Farther up that wire is a fusible link, check that to be sure the solder hasn't melted off the link. this will shut it down to.

Loose Connections at the Amp Gauge (If So equipped) .

Loose, wet or Corroded Connections Between the Firewall and the Starter Harness, Good test, is with it running, shake the harness, If it dies, look in there.

Hope it helps.
Doc

[/size][/color]

[malibuman66]

Originally posted by docvette
[color=lightblue][size=3]Doc here

Thanks for the info...

The place to look:
(since the Church Doesn't Exorcise inanimate objects anymore...)

Check the Solenoid on the Starter, Be sure it is Tight on the Starter, and the Cables are Secure to it. The 10 Gauge Red wire on the main terminal with the Battery cable can turn the system off if it is loose, so be sure it's tight.

Farther up that wire is a fusible link, check that to be sure the solder hasn't melted off the link. this will shut it down to.

Loose Connections at the Amp Gauge (If So equipped) .

Loose, wet or Corroded Connections Between the Firewall and the Starter Harness, Good test, is with it running, shake the harness, If it dies, look in there.

Hope it helps.
Doc

[/size][/color]

Fusible link , there is no fusible link in this car and there never was, don't tell me thats my problem. Alot of people I talked to went over and over and some said it was not nessacary and Iam abou 99 % sure it does not show it in the wiring diagram , but don't quote me on it. I don't have it in front of me . When the car starts it starts without a fusible link

John

[docvette]

[color=lightblue][size=3]Doc here:

If the wiring is STOCK and unmodified... you have a fusible link (S) Not an option from the factory...

It will be on the wire coming from the Solenoid back to the Ignition Switch,

OR

on the Horn Relay, and 3 terminal regulator going back to the cabin...or both...But there are there!

They will be taped into the harness and consist of nothing more than a few smaller Gauge wires soldered into a lead crimp with line on one side and load on the other.

Doc [/color][/size]

[horvath]

Doc's right ... fusible links are standard (and necessary) on certain connections.

Fusible links are very important in the engine area:
Check This Out

Alan
54 Chevy Pickup

[Onestreetrodder]

oooooooooo

[57 Chevy]

Hate to jump in here, but if the fuseable link is shot, then it wouldn't start at all. Would it?

With all that new stuff, my guess would be a wire connector is loose and when you move the right combination, it makes contact. Or even just the netural safety sw. is out of adjustment. Just my 2 cents.

[poncho62]

My Pontiac does the same thing...sometimes starts sometimes nothing. It's like the power isn't getting to the "S" terminal of the starter. I finally put in a separate pushbutton switch under the dash that goes from the battery to the switch to the "S" terminal. When the ignition switch wont power the solenoid, I hit that switch and it starts.

[docvette]

Doc here,

Gawd..Who dug up this dinosaur??? It's over a year in a half old..

Anyway, gives me a chance to re~read it and clear up a mistake I made..

If the wiring is STOCK and unmodified... you have a fusible link (S) Not an option from the factory...

Chevy Didn't Start Installing Fusible links until 4 years later in the 1970 models..STOCK 66 would not have had one..HOWEVER the aftermarket harness he installed SHOULD have had one..and if not,is a Fire risk without one.

An intermittent Neutral Safety switch WOULD cause this type of problem (either Mechanical, or Electrical) As 57 Chevy Noted

The way a link COULD cause this, is if on a 3 wire or trident link, (such as older GM used) had one wire melt , or pull from the junction slightly and was just sitting in a ball of melted tape goo ...It could become intermittent on that one tap only..the other two remaining constant. If hooked up correctly, They should support the power to the Ign Switch (Switched power) , Unswitched power at the buss (Hot at All times) and Alternator. Which wire would be a matter of chance, but would effect that load..

Another common cause of this problem exists in the starter solenoid, the contact shoe on the inside of the solenoid going bad, pitted or carbonized contacts, or uneven spring pressure on the contact shoe, will cause the contact not to conduct. ON the other side, the phenolic terminal block can become warn and loose, allowing the terminal to move about.

Of course the Ignition switches do fail quite often also, but basically if you don't get 12 volts down to the "s" terminal when in "Start" mode, on a DVOM it's either the switch, N/S or link..just back track the circuit.

My error Being corrected, I can now sleep at night again..

Doc

[IgnitionMan]

OK...well....after all that, lets get down to checking the ignition now...

You will need a helper and a voltmeter capable of reading 20 volts DC current, and an assistant.

The meter has a red wire, connect that to the plus (+) terminal of the ignition coil

Meter also has a black wire, ground it to the engine, carb stud, etc.

With the meter connected, remove the coil wire from the distributor cap, and hold it 1/4th ionch from an engine ground, have the assistant spin the engine over. You should have both spark from the coil wire, and a near full battery volts reading on the meter as long as the engine is spinning over. This would indicate the starting volts are fine if the system is working.

If you don't get spark, and/or don't get a volts reading, then there is no volts energizing the coil and ignition system on start. This circuit comes from the R terminal of the solenoid, to the + side of the coil. It functions in the start position only.

After testing the above, leave the key in the run position, and you should see volts on the meter, in the range of almost full battery volts with the engine not running, lower, down to someplace near 9.5 to 11.5 with the engine running at idle.

Please post the results for us.

A fusible link either works or burns completely out. When they blow, just about everything on the vehicle goes dead electrically.

[docvette]

Doc here,

Well, Since this thread is almost a year and a half old..I assume He Found and corrected the problem, Maybe He'll post us back and tells what was the malady..Via auto~generated Email..

As Always good Ignition Information for spark testing.

Lets get to the Crux of the problem..If you can't CRANK the engine, you can't perform any other tests..Which was the original Complaint, Intermittent power to the Vehicle Buss system.

didn't start due to lack of fuel, so pumped gas and went to start again, nada, nothing, like dead, like no battery in car.

It would appear that you have replaced all the parts associated with this type of INTERMITTENT failure...

I replaced the ignition switch is it possible that I could have a faulty switch again, the neutral safety is new, the starter is only 6 moths old , new wiring harness, new voltage regulator, actually all new electrical and mechanical components in the engine compartment.

The possibility remains that the Neutral safety switch is mechanically out of adjustment (on the wicked edge) Or the mount is loose, bent or moving at times when the linkage contacts it. This would Cut Power to the "S" side of the Solenoid and defeat Cranking.

A loose Main System Buss wire (The 10 gauge at the main battery cable at the Solenoid bolt, or elsewhere on a single terminal at or near the battery, or Voltage regulator to horn relay) Would also have the same effect, although Everything would go dead..Lights radio, dome lamps Etc..you never said if that was the symptom , just: " like it had no battery" , So I must assume it is/was so..

If It were just the Crank function going dead, It then could be, A bad solenoid, The Contact shoe not conducting between the Main Battery cable and the Starter motor lug due to bad, burned or mis~aligned contact shoe..You said: "the starter is 6 months old", Does that apply to the Solenoid also ? or is it the old one on a new starter?..Remember: Because it is new (or near new), doesn't mean it will always work, 'It may be defective.

More rare, but does happen, Is on the 2 and 3 wire Fusible link (Yellow Crimp)OR 2 or 3 separate Fusible Links are applied (blue Crimp), Where the device wires feed into the link cable, The installer performed a Bad crimp and one of the wires pulled out of the joint, or had heated up and separated from the link pigtail.


This will leave one leg of the Main feed Effectively Dead..Or If slightly touching with Engine/Harness movement Intermittent. It IS a PITA to detect, and is rare..But I've seen maybe 5 in 37 years..Of course this is mute if the NEW harness does not have links...(Which it should!)

Other things that COULD effect the system, Is a loose fire wall plug, not all the way seated in when installing the harness..Check that too..

Bad (loose ) Ground buss system, loosing ground between the battery, and the frame/block at random.

AS I said, "Just Because it is New, don't assume it's good" Recheck the Switch, and Neutral safety switch, and the solenoid.

Hope you Have already found the problem by now, and If so, please post back with the answer!

Doc