Wagon frustration

[Oldiron440]

Verify engine ground also, should be a decent ground strap.

 

[Mikes5thAve]

Unless its been modified the negative cable should go directly to the front of the engine. Just make sure the bolt is still tight and cable isn't badly damaged.
That's not too likely to be causing the starter problem when it worked properly shorting out the two cables below.
There should be a ground from engine to body at the back of the engine on the driver side and sometimes one at the bottom on the same side.

 

[Kramer79]

Thanks for all your help, when I bridge battery to solenoid (it is a new relay) the battery shows a current draw - dips to 11.8, but still won’t crank. Should that ignition switch always have power to the relay, or only when the key is turned? I’m guessing it is the ignition switch - but I may try the neutral safety and ground too 20$ in parts still cheaper than a tow and mechanic...

 

[Kramer79]

Is this the starter switch? Can’t think it would be anything different... thanks

 

[Mr C]

Have you checked the fusible link? Had that happen once. Would crank from the relay or across the starter, but even then no start until the link was replaced.

 

[Kramer79]

Where is that located? I have not checked that... I checked the fuse box - didn’t notice anything blown?

 

[Mr C]

The fusible links are front of left front wheel house on the engine side of the 40 way disconnect into the car. My FSM shows 2 links related to ignition switch and the electronic spark control system (engine computer). Page 8W55 of the FSM.
We can do some easy tests that should determine if it's a blown link.
Have you got a volt meter?

 

[Mr C]

By the way a fusible link is a wire that acts like a fuse. They are designed to burn through if too much load or a short happens.

In case you didn't know.

 

[Kramer79]

I have a volt meter... I did see a few of them ...

 

[Mr C]

Glad you have a meter. I have a few FSMs covering M bodies, so I think we can fix this.

What year is you car? I want to be sure I use the proper/ best FSM in trouble shooting.

The fusible links are the first "stop" that can blow before power gets into the car to the ignition/ fuses etc. (which you said fuses are all good). So we can determine if a link has blown/ partially melted depending on what they feed.

My understanding as of now:

1) When you bridge the starter contacts it turns over. Did you do this with the key in run position? I presume it did not start and run.
2) Did you apply power to the brown wire on the relay? Did it crank then?
3) You mention you have intermittent cranking sometimes when you turn the key (which is weird). Does it still do that?

Please get back to me and we'll go from there..

 

[Kramer79]

Thanks so much!

1981 diplomat wagon /6

1. Cranks when key is off, and in run position. I didn’t do it long enough in run to attempt a start.

2. Brown wire applied, no crank.

3. Very infrequently- but yes it will kick occasionally- that’s why the fusible link has me thinking...

 

[Mikes5thAve]

Fusible links burn up when there bad. Easy to tell.
Shorting the two wires at the starter relay doesn't need key on. All its doing is putting power where the key would put power to make the relay work. If it cranks you know the problem is the ignition switch or power thru it. If it doesn't crank the problem is the relay or starter side of it.
You already know the ground and thick positive cable to the starter is good or else it wouldn't have cranked when you jumped the two wires at the starter.

 

[Mr C]

I've seen it where links partially melt causing intermittent function which is why I mentioned it. Your intermittent kick symptom has me wondering if it could be that.

First I have a question about your brown wire comment " Brown wire applied, no crank"

Did you just put it back on the post on the relay or did you run a 12 v jumper to it? If you ran a jumper and there was no crank then there is a problem with that brown wire (broken, corroded whatever). It should kick just like when you bridged the starter.

Running the 12v jumper to the brown wire is doing the same thing as when you bridge the starter contacts, only one step farther up towards the ignition switch.

So if you have not done that unplug the brown wire at the starter relay...then please run a wire from the big red wire on the relay (should be 12v...you can check with your meter before running the jumper) or right from the red post on the battery.

Please verify what you did with the brown wire and we can move from there.

 

[Kramer79]

Connecting brown wire to battery makes a “clunk/click” but doesn’t engage the starter fully/at all. If I move the key to run and try this - nothing happens

 

[Mr C]

Just did this test on 2 of my cars and got an immediate strong kick response in both of them.

Question...confirm that when you bridged from red to brown at the starter relay, that you did this to the solitary brown line below the red and not the brown on the big connector beside the red?

Just checking...

 

[Kramer79]

I used the two connectors right on the starter big red to little bolt..

 

[Mr C]

Hmmm...that last post sound like when you bridged the starter posts...

We are at the Starter relay now.

This is what I want you to do:

Unplug this wire from the relay:

Jump it to the red wire like this:

Should turn over like when you bridged the two nuts at the starter motor.

Let me know what happens.

 

[Aspen500]

May have been mentioned already but, a way to verify if the neutral switch is a problem, there's 3 way connector near the right rear of the engine compartment. It'll be close to the fender brace and the wiring runs down to the trans. If you ground the brown wire , that will bypass the switch since it grounds to allow crank. Doesn't sound like what you're describing but, won't hurt to check.

 

[Kramer79]

Yes, it cranks. I thought the brown wire was the top left one in the clip, so it cranks (key off) when I do that!

Hmmm...that last post sound like when you bridged the starter posts...

We are at the Starter relay now.

This is what I want you to do:

Unplug this wire from the relay:
View attachment 42084

Jump it to the red wire like this:
View attachment 42085

Should turn over like when you bridged the two nuts at the starter motor.

Let me know what happens.

 

[Mr C]

Okay, since that works, next as suggested is to verify if it is the neutral safety switch.

Try starting in Neutral, then in Park.

Report back.