Is it the ignition switch or relay that's failing? ('74)

[Mid70's Chrysler Fanatic]

On occasion, the ignition switch on my T&C does nothing when I turn it to START. It doesn't matter if the shift lever is in Park or Neutral. If I turn the key to ON and jump the relay terminals, it'll start fine. In the thread, "Intermittent Ignition Switch Failure", the OP states that his problem (on a 1969) occurs at a certain temperature and humidity. My intermittent problem doesn't yet happen often enough to identify any circumstances that provoke it (except that rain doesn't cause it).

How would I best identify the source of the problem? I did replace the relay a couple years ago when I thought it was bad, but the random quality of Chinese aftermarket parts being what it is...

 

[Davea Lux]

On occasion, the ignition switch on my T&C does nothing when I turn it to START. It doesn't matter if the shift lever is in Park or Neutral. If I turn the key to ON and jump the relay terminals, it'll start fine. In the thread, "Intermittent Ignition Switch Failure", the OP states that his problem (on a 1969) occurs at a certain temperature and humidity. My intermittent problem doesn't yet happen often enough to identify any circumstances that provoke it (except that rain doesn't cause it).

How would I best identify the source of the problem? I did replace the relay a couple years ago when I thought it was bad, but the random quality of Chinese aftermarket parts being what it is...

Run a continuity check on the neutral safety switch, if it shows open or has high resistance it is bad. The relays made in china are not the best quality, read piss poor, you can carefully remove the cover of the relay, often there will often be rust or other corrosion in the internal parts because of poor plating. You can clean off the corrosion and then the relay will work, but the unit will keep corroding. Next check the terminals that hook to the relay, they some times get loose to where they do not provide a good contact. Usually crushing the terminals lightly with a pair of pliers to tighten them up will solve this problem.

Dave

 

[Mr C]

Is your 74 US production with mandatory seatbelt interlock, or Canadian without? (seeing IA, I presume US, but you never know).

Is your seatbelt buckled? No cargo in passenger front seat? If it is still connected and functioning, it can seriously complicate the issues.

Tilt/ tele wheel or not? Tilt tele wheels use Delco ignition slider switch prone to failure.

 

[mikedrini]

Had a similar situation with my 64 NY and it sounds like the NSS as was stated by Dave. That's what my issue was. I noticed on occasion I would have to hold my push button Neutral down when turning the key. Once I changed my tranny filter, it allowed me to look into the tranny from underneath to readjust the NSS, problem went away.

 

[Mid70's Chrysler Fanatic]

Is your 74 US production with mandatory seatbelt interlock, or Canadian without? (seeing IA, I presume US, but you never know).

Is your seatbelt buckled? No cargo in passenger front seat? If it is still connected and functioning, it can seriously complicate the issues.

Tilt/ tele wheel or not? Tilt tele wheels use Delco ignition slider switch prone to failure.

It has the seatbelt interlock. The sensors under the front seats have been unplugged, and it gives me no interference. (I tend to buckle up after starting the engine.) The column is the standard one. The aforementioned trouble has been in the past month, and I drive this wagon a lot.

 

[Mid70's Chrysler Fanatic]

Had a similar situation with my 64 NY and it sounds like the NSS as was stated by Dave. That's what my issue was. I noticed on occasion I would have to hold my push button Neutral down when turning the key. Once I changed my tranny filter, it allowed me to look into the tranny from underneath to readjust the NSS, problem went away.

Yeah, I've got this problem with my Dakota, off and on. When it fights back in Park, I just move the lever to N and fire 'er up.

I assumed that the NSS is okay because the wagon wouldn't start in either P or N. Do these switches ever "go" such that neither position works?

 

[Davea Lux]

Yes. As noted above, put the car in park and run a continuity test on the NSS.

Dave