Intermittent ignition help

[Datsun78]

'69 Barracuda convertible, 318, auto trans, Pertronix ignition module. Have intermittent problem where car won't start. Have lights, horn, etc, but no click or starter engagement. Shifting trans, repeating turning key, tightened positive battery cable has no effect. If left for a few days or weeks, will start up and run fine, until happens again. Replaced neutral safety switch and connector, but no change. No discernible pattern to issue, other than has always happened in the garage(fortunately).

Any guidance to what to check?

Thanks!

Mark

 

[crj1968]

Check power at positive side of coil with key in RUN.
if you have help check it also while cranking...

 

[TT5.9mag]

Sounds like a common bulkhead wiring issue. Remove the bulkhead connectors, look for contacts that have signs of heat deterioration and or corrosion. Clean all contacts and reassemble.

 

[Murray]

Are you using the original style starter? If so, the contacts do go bad in the solenoid causing an erratic starter behavior.

 

[67Dart273]

'69 Barracuda convertible, 318, auto trans, Pertronix ignition module. Have intermittent problem where car won't start. Have lights, horn, etc, but no click or starter engagement. Shifting trans, repeating turning key, tightened positive battery cable has no effect. If left for a few days or weeks, will start up and run fine, until happens again. Replaced neutral safety switch and connector, but no change. No discernible pattern to issue, other than has always happened in the garage(fortunately).

Any guidance to what to check?

Thanks!

Mark

Go over to MyMopar and download a free service manual. You may have to settle for Dodge vs Plymouth. I realize it may not have "rally" cluster wiring included. Also go to their wiring section and get the 2 page aftermarket diagrams. For some reason these are now zipped, often into a big package of several

You need a meter, test lamp, and some alligator jumpers if you don't have

Pull the dark wire coming off the starter relay which goes down the firewall to the transmission safety switch. Clip your meter, on DC volts to the now bare starter relay post (from which you just removed the wire) and ground the other probe. Twist key you should have voltage. If so, ground the post to which you connected the meter, make SURE the trans in in P or N and see if it cranks.

If not and if you had voltage to the meter in the first test, the relay may still be defective. With the NSS post still grounded pull the other flag terminal off--yellow goes to key "start" signal, jumper power from the "big stud" on the relay to that post. It should crank. If not

jumper directly from the "big bare stud" to the other "big square and bare" post and it should crank. if not you have a problem at starter/ starter wireing, bad wire from starter relay "square post" to the starter, or possibly a battery cable problem

 

[cudamark]

'69 Barracuda convertible, 318, auto trans, Pertronix ignition module. Have intermittent problem where car won't start. Have lights, horn, etc, but no click or starter engagement. Shifting trans, repeating turning key, tightened positive battery cable has no effect. If left for a few days or weeks, will start up and run fine, until happens again. Replaced neutral safety switch and connector, but no change. No discernible pattern to issue, other than has always happened in the garage(fortunately).

Any guidance to what to check?

Thanks!

Mark

Sounds like you have a no-crank problem, not a no-start problem. When it happens, can you get the engine to crank by triggering the starter relay under the hood? (careful that the car is in park doing this!) If not, it could be the relay, starter, starter solenoid, a bad battery cable connection, or the power wire to the relay. If it will crank from triggering the relay, it could be a bulkhead connection problem, ignition switch, neutral safety switch, or wiring between those items.