94 4.0L OHV starter solenoid and relay

[rumblecloud]

Been scrounging around trying to find the right place to post this. It's a common problem that I've seen in a bunch of different places. It's the dreaded "CLICK" when you turn the key to start. I know RonD has thrown down a lot of help on this as well as many others. I just got the girl back on the road a week or so ago and everything has been great. Took her to the store and back. Parked in the barn when I got back. Went to start it a few hours later and got the click. Battery voltage is 12.53 at the posts. Same at the relay. I did not measure at the starter motor, but pulled it and bench tested it (well more like fender tested it). Everything works as it should - motor and gear spins up and the solenoid kisks the gear out.
So now I'm at the relay. I have the 4-poster and am playing with the multimeter looking for continuity. I say playing cuz I do not understand. When I measure from the "S" post to ground, I get an audible beep and the numbers in the pic - 3.2 Is that good or bad AND what else can I measure to help determine if the relay is bad?


It starts at 3.5 then settles down to 3.2.

As always, thanks. I know you prolly get tired of answering the same questions, so if you can point me somewhere - No Dirtman, not there - I'll be happy to go.

 

[RonD]

The inner fender mounted starter relay can have 4 posts, only 3 are used

The two larger posts are the "power posts", they are connected together when relay is Closed/activated

The smaller "I" post is not used(this powered the ignition coil on older models, just FYI)

The smaller "S" post is used, this goes to the Coil inside the relay, when the coil has 12v and Ground it becomes a magnet and pulls the relay closed, connecting the two larger posts together

The relays base is the Ground for the coil inside
And the coil is just that, a coil of wire around a metal tube, so "S" post will show as a ground if tested with OHM meter or continuity meter/tester

So that's correct, same as a 12volt light bulb would test as a ground if testing on the 12v terminal, its just a coil of wire in a vacuum

If you apply 12v to the "S" post the relay should "Click" closed, if not check its base ground screws, remove them and reinstall to make sure ground for relays coil is OK, if still no "click" then replace relay


If you use a jumper wire between the two larger posts the starter motor should activate, if starter just "clicks" then the larger 12volt battery cable going to the starter can't pass enough amps
Or the larger negative cable going to the engine can't

Starter motor needs about 60amps flowing thru it to turn the engine, "flowing" is the key word
Electricity must flow thru a device to power it, if the device needs 60 amps then 60amps must flow from positive terminal on battery and same 60 amps back to negative terminal, if either is limited to say 10 amps then no starter motor


Yes, studies now say DC current travels from negative to positive, but its really not important in this example, is it, lol

 

[rumblecloud]

You are the da bestest!!
K so I reinstalled the relay and am getting a loud click. I have not reinstalled the starter motor ( I'm waiting for another part and the starter motor would be in the way).

So it's clicking - that doesn't mean it's okay, or does it?
I know from reading other posts on this topic that the Neutral Start Switch can also be an issue when the shift lever doesn't fully engage PARK. And since I just replaced the shift cable....

When I put the starter motor back in, hopefully tomorrow, I can futz with the shift lever and see if that's the cause. The backup lights work BTW - not sure what that means but I saw that in another post too.

 

[RonD]

Does the inner fender relay "click" when you turn the key to START while in Park?

If so then Neutral switch(NSS) is OK, if not try in Neutral, if it works in Neutral then yes, may need to adjust cable or NSS switch

NSS, in 1994, is a plunger type switch, it is screwed in above a Cam inside the transmission on the shift rod
As you move the shifter the cam moves NSS plunger up or down, making and breaking contacts inside it, including the Back Up Lights

NSS is between ignition switch and starter relay

Ignition switch-------------------NSS----------------starter relay-------------starter motor

So if Relay is clicking with key in START position, then all is well from key to the inner fender relay, wiring wise

 

[rumblecloud]

Does the inner fender relay "click" when you turn the key to START while in Park?

If so then Neutral switch(NSS) is OK, if not try in Neutral, if it works in Neutral then yes, may need to adjust cable or NSS switch

NSS, in 1994, is a plunger type switch, it is screwed in above a Cam inside the transmission on the shift rod
As you move the shifter the cam moves NSS plunger up or down, making and breaking contacts inside it, including the Back Up Lights

NSS is between ignition switch and starter relay

Ignition switch-------------------NSS----------------starter relay-------------starter motor

So if Relay is clicking with key in START position, then all is well from key to the inner fender relay, wiring wise

Yes, the inner fender relay clicks in both Park and Neutral, so the wring is good. I'll be reinstalling the starter motor tomorrow morning.

While is was reinstalling the relay I noticed this small plug and was wondering about it's purpose. Any ideas? It has a plastic insert that looks like it's just for protection of the innards. It's the smaller plug in front of the OBD1 test plug. Thanks.

 

[RonD]

That looks like the SPOUT connector, it is used to service the spark system or time a distributor, if there is one, which you don't have
It needs to have plug inserted or you will lose Spark advance from Computer, i.e. load advance

But should have 2 pink wires in 1994, so might PCM shorting bar, dark green and grey/red wire, but also should have plug inserted

 

[gaz]

That certainly looks like a SPOUT, I didn't realize the DiS still used them???

 

[rumblecloud]

Cool thanks. I put the plastic plug back in and am leaving it be...

 

[rumblecloud]

UPDATE: Put everything back in and all is good. Did not replace anything. Used all same parts. My guess is that maybe there was a loose connection or perhaps the shift lever had a bad day even though I tried park and neutral.

It's worked fine now for a couple of days. Kinda spooky though not knowing what caused it and wondering if/when it will happen again. I bought the solenoid relay and keep it in the back just in case. I love the sound of all the tools rattling around in the back.