Ωhm

All dash lines connect to the starter relay (batt) terminal.

Follow the electrical manual.

Reason for my concern on Cruise/Trans switch logic. TCU_C10 seems to be a voltage sensitive digital switch. This digital switch tells the TCU processor when the brakes are being applied and too disengage the torque converter (S3) from lockup, if conditions are such that the torque converter is in lockup mode. TCU processor controls S3 no differently than the way it controls S1 & S2. That is too say, TCU processor controls a high side driver (12vdc) to component (in this case S3) to ground. Same applies to S1 & S2. Even the fuel injectors are controlled the same way, high side driver (12vdc) to component to ground, but that's a different module (processor). Circuit function (the wiring). When Cruise/Trans switch is in the open position, voltage is being applied to TCU_C10, since no current (amps) is flowing in the circuit. Once Cruise/Trans switch is closed and ties the circuit to ground, current flows and all available voltage is dropped across the resistor pack (1.2kohms). The two (2) conditions are TCU_C10 sees 12vdc (brakes are not being applied) or 0vdc (brakes are being applied). So this is how I see the circuit wiring and how I see the circuit function (purpose). Please advise on any other explanation.

I (we) are only as good as the documentation and yes, documentation has been known to be incorrect. I still don't understand how flipping the switch logic will make things okay.

I still think you need a switch, when installed in the vehicle, where both switches (Brake & Cruise/Trans) are closed when the brake pedal is depressed.

Welcome to the Forum. Might take 10 or more posts inorder for the Want Ads to work. Check out this thread (link) for electrical questions, its contains diesel schematics. Not the easiest to read, but its the best I've found so far. Click Here

Looking at the wiring diagrams (88ELECT, pg20,pg71) both switches close when brake pedal is depressed. How should we address the NC & NO verbiage, when installed on the vehicle or out of the box and on the bench?

Yes you could use relay logic here or could one just take the output of the correct contacts (connector connected) and feed the output wire (connector not connected) of the other set of contacts. This would a$$ume that all current requirements are meant and that the switch is as I claim.

Out of the box and on the bench, doesn't that switch (SL186) have one set of contacts NC and one set of contacts NO? I would think you need both contacts to be NC.

Its the Cruise/Trans Switch. Serves two purposes: Vacuum dump for cruise when brake lights are ON. Disengage Torque Converter when brake lights are ON.

Even with your cap on, G102 (CAB & IP ground) finds G103 (Engine Compartment ground) through Splice G and then through C100_G4 to G103. Beefing up G102 is a good thing, but G102 still needs to find G103.

A change in connectors usually means something else has changed. Its like the manufacture don't want you using incompatible parts.

Not sure how close it is to the hood release cable, but it pigtails out of the harness with the wiper switch connector and the headlamp delay module (if equipped) connector.

I think you just got a bad starter motor by the symptoms posted.

Pin F (BAL) is connected to SOL internally.

Check ground G102 located under the dash. This ground is used by both the voltmeter and oil pressure gauge. Yes its tied to G103 (dipstick) through Spice G, but still needs to be checked for proper grounding.

I've notice that both old and new relays have Pin F. I believe that pin feeds (BAL circuit) the fuel pump during CRANK, bypassing the ballast resistor. Connecting Pin F to BATT (threaded stud) would cause fuel pump to run constantly.

You guys nailed it.

Yea, need a end view picture showing the pin cavities.

If this is a relay block, its for the cooling fan. Relay is missing.

This thread talks about fuel pumps. https://forums.4wdmechanix.com/topic/892-1986-jeep-cherokee-25l-low-speed-lack-of-power/

I know what you mean, but Michigan will never stop using salt, not until all the inland lakes turn to salt water caused by salty road runoff. Check out WIPP, salt that glows. http://www.wipp.energy.gov/fctshts/salt.pdf

Your vehicle nightmare story coming soon to a dealership near you.

True, even power steering, power brakes and automatic transmissions were new features when they first came out.

My vehicle has A/C, but driving around town I like all 4 windows down. More & more I now notice starters engaging when traffic lights go from Red to Green. Is this technology going to dominate all vehicle in the years to come? It kinda makes me laugh when I hear this.