318 Ignition/Start Issue

[RonHall76]

Have a 1967 W200 with a 318 that was "period" customized - Carter carb, Edlebrock intake, headers ...

I upgraded to Petronix with their suggested coil. Added a new starter. Just changed all the plugs the fuel filter, charged up the battery (Optima) and it has been running great (had it out last week).

Went out to use it for some chores today ... and nothing. Immediate thought was to hook up a jump from a battery charger/jumper (thinking I had left something on) and nothing. Not even a click.

Checked battery and it was good.

Turned ignition switch to run and accessory positions and got stereo to run fine and dash to engage. Nothing/all went dead when I turned to start position.

Have not replaced the ballast resistor (probably original), has the original ignition, and also original spark plug wires. Quite a bit of the wiring is original.

Have run/owned a lot of heavy equipment over the years and it seems like what I would call a "wiggle jiggle" situation ... like a failsafe switch is out of joint. But know of none on this truck.

Wondering if it is the ballast resistor or just the ignition switch.

Have spare trucks and someone who knows more than I do on electronics but wanted to see if it might be something I could do/try.

Question: If it is the switch - Just finished a Painless rewire on a 68 318 and added a new ignition switch. Found the switch ok but could not find a matching wire fitting that I could wire to and then plug the switch into. Had to run wires into ignition and ended up with a loose wire the other day. Wondering if anyone knows of a source for a fitting? That way I could change out on both trucks.

Always something, but when they are working they are tanks.

[dodgeboykim]

Have you tried jumping starter relay to see if it turns over. Ballast has nothing to do with engine not turning over.
If it turns over then check at switch and wiring to relay.

[712edf]

If this were an automatic, I would say check the Neutral Safety Switch on the transmission & the wire from it to the starter relay. Since this is a 67 W200 I am guessing you have a manual transmission.

Anyways try the jumping across the relay as dodgeboykim suggested.

Bucky

[58pwrwgn]

Starter relay

After putting the truck in neutral. Use a screwdriver to jump the battery wire at the starter relay and the red wire the goes down to the starter solenoid. This will tell you if everything for the starter is good.
Check that your starter relay has a good ground to the body.
Check that the brown? Neutral safety wire to the relay is grounded.
With someone holding the key to start. The yellow wire to the relay should have 12 volts.

[RonHall76]

Hi folks,

Bad starter relay.

My friend that helps me with the electronics on these rigs got a chance to help me check this yesterday. His day job is an auto electronics tech (which means he is always helping friends on the weekend).

FYI - We/he used the Power Probe III he got me to buy a while back. https://www.tooldiscounter.com/product/ ... nIQAvD_BwE

After watching him work his way through the process (it helped to have me position the key), I felt a bit sheepish for adding this thread because it was very similar to this post from 2019 viewtopic.php?t=42760 The big difference is in the title ... having to do with the "solenoid" and gets clarified at the end of the thread -

"The solenoid is on the starter, and is operating correctly since the truck starts by jumping.
The starter relay is on the inner fender. By definition, it is not a solenoid.
Which one are u referring to?"

Because I had replaced the starter someone had explained to me that the solenoid was on it when we did that.

One thing that was different from the older thread was that using the Power Probe III he was able to pull out the ignition and find which connection was supposed to send power to the relay. Probe even has a light to aid visibility.

What did get explained to me yesterday is that often times one of the functions of the start positions on the ignition is to cut all power to almost every other circuit on the car to send it to the key ones needed in ignition/starting .... which explained why I was losing the radio and dash.

He did this all in 10 minutes ... including the explanation. Always amazes me. Even invited me over for a drink later in the afternoon.

Appreciate the help and timely feedback/input from the forum. Know more than I did a couple days ago.

Make it a good day.

[712edf]

Starter relays seems to be more reliable than the other components of the cranking & ignition system. I have never had one fail.

Bucky