starter relay issue

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I am REALLY troubled by this "trend" which has been going for a long time, now. There's been rants on how bad various--old brand name--front end parts are. When I got my Dart running, I bought an NAPA dimmer switch. I didn't drive the Dart much, certainly not at night. I doubt that dimmer had 2 dozen actuations, and it simply fell apart.
 
67Dart273 said:
I am REALLY troubled by this "trend" which has been going for a long time, now. There's been rants on how bad various--old brand name--front end parts are. When I got my Dart running, I bought an NAPA dimmer switch. I didn't drive the Dart much, certainly not at night. I doubt that dimmer had 2 dozen actuations, and it simply fell apart.
Click to expand...
I buy parts at NAPA quite often but I have had quite a few issues with their electrical components.
 
67Dart273 said:
This brings up a point........HOW ARE they failing, Denny? Is the coil going open or the contacts failing. OR IS THE ENGINE just rattling them apart from vibration?

The last thing that comes to mind..........same starter? Maybe you have a "partially shorted" starter solenoid which is drawing way too much current. If this is a mini starter it would be easy to check current draw, but I don't know what the "average" is. You'd have to check several others to get a baseline

If you are using the old original type starter, this gets more difficult. If you are familiar, the old starter solenoids had TWO windings.........a very heavy "pull in winding" and a "hold" winding.

The "pull in" winding is in series with the starter internally, and it only engages during pull in. Once the solenoid contacts are closed, it is bypassed, leaving only the "hold" winding.
Click to expand...


Starter issue seems plausible but playing devils advocate, if it is a back feed on the ignition would the starter not be engaged all the time. These are pretty simple high current relays that only get exercised at full right turn yes?
 
Not necessarily. I've seen where the "run" feeds through the resistor.....to the coil.... back to what should be the "brown bypass" circuit. This is typically when someone miswires, but it could conceivably be from a bad ign switch. The coil draws current in park or neutral, not enough to engage. I bet this is more poor quality, vibration, or a starter solenoid partly shorted.
 
Not sure if connected or related but when the relay first fails, I short across it with a screwdriver and after a few bumps....sometimes can get it to start thru the ignition switch...but after once or twice at the most, no more go.

Swap out relay....perfect again.????
 
My guess is insufficient voltage to relay coil winding. A voltage below 10V, is likely not enough. The circuit involves, NSS, bulkhead connections, IGN2, fusible link and other connections. A voltmeter placed to measure relay coil while cranking would be helpful for trouble shooting.

Sufficient voltage there is important, when the relay coil is energized, the magnetic circuit pulls the contacts together, there is a spring that works to hold them apart. The magnetic circuit strength increases with current, and that is based on supplied voltage. A weak pull-in, results in greatly increased contact erosion.

Seems like changing relays is not the root cause of problem. Perhaps low voltage to relay coil is, let a meter be your friend.
 
I pulled apart the most recent failed relay and it looks brand new inside....no broken or scored anything...nada

while at Ross's, HemiMark pointed to what looks like a flasher /relay mounted on the inner fender near the firewall and asked...what's that for?....I could not remember, but got to thinking that might be the issue. It could be part of the 1974 emissions (leaner burn) mandate and is messing with the timing/ electrical. Since the car had factory electronic ignition ...I used all the factory harness. It is not horn related. ....horn works when disconnected.

anybody know what it is and it's function?....from memory (and Margaritas at Ross's) 3 wires from it.

I would post a picture, but I'm 30 miles away from the car at present.
 
HemiDenny said:
I pulled apart the most recent failed relay and it looks brand new inside....no broken or scored anything...nada
Click to expand...

That observation suggests relay might be good. First test might be hook up leads and energize relay coil from battery, see if coil pulls in contact. By inserting a thin paper strip in between stud contact, see if it is held tightly, when contacts close.

If the relay works, use meter, and post #31 along with FSM wiring diagram to find voltage drop in relay coil circuit.
 
HemiDenny said:
I pulled apart the most recent failed relay and it looks brand new inside....no broken or scored anything...nada

while at Ross's, HemiMark pointed to what looks like a flasher /relay mounted on the inner fender near the firewall and asked...what's that for?....I could not remember, but got to thinking that might be the issue. It could be part of the 1974 emissions (leaner burn) mandate and is messing with the timing/ electrical. Since the car had factory electronic ignition ...I used all the factory harness. It is not horn related. ....horn works when disconnected.

anybody know what it is and it's function?....from memory (and Margaritas at Ross's) 3 wires from it.

I would post a picture, but I'm 30 miles away from the car at present.
Click to expand...

Post a photo!!!

I didn't realize this was a 74. You don't still have the seat belt interlock box do ya? This has a reset button on a horn relay looking box under the hood. The starter relay "start" wire goes through that. If you have it, you need to jumper the two yellows together

This thing here.........

100_0894-jpg.jpg


So far as your dissection, I'd be making sure that the relay is actually what is failing. Hook the two spade connectors to a battery........does it pull in? If not the coil is bad. If so, inspect the contacts. If they look fairly clean, there's likely nothing at all wrong with the relay
 
67Dart273 said:
Post a photo!!!

I didn't realize this was a 74. You don't still have the seat belt interlock box do ya? This has a reset button on a horn relay looking box under the hood. The starter relay "start" wire goes through that. If you have it, you need to jumper the two yellows together

This thing here.........

View attachment 1715052239

So far as your dissection, I'd be making sure that the relay is actually what is failing. Hook the two spade connectors to a battery........does it pull in? If not the coil is bad. If so, inspect the contacts. If they look fairly clean, there's likely nothing at all wrong with the relay
Click to expand...

on the photo...as stated, I am 30 miles away from the car...be back there after the Holiday.

it looks like a little different than that particular one, but perhaps that is what it is. The seat belt circuit in the interior is long gone

I took it apart for a look-see inside while waiting to leave for Ross's and ran out of time. I will add some juice to it when I get back to the shop.
 
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