Ωhm

I like the story of 1-2-3.

Do the Hazards work? If not, double check the hazard/stop fuse.

Nope. This was mine, buried in a box, buried in the basement. Went back to the house (boy lives there now) looking for some vintage lens for my camera, which I didn't find.

Idle Air Control Motor Tester (4.0L)

Belt routing, correct? Belt tension, correct? New/old belt? Check and make sure that the belt is not just slipping.

Distributor needs to be indexed, not timed. CPS determines set base timing. ECU will advance timing, based on inputs from that set base timing mark. Cruiser Tip 13; Distributor Indexing

Okay. Just needed to be sure your fuel pump wasn't getting its voltage just from the Starter Relay during CRANK.

D1_5 & D1_6 would be fuel pump circuit tests. D2_4 checks for IGN SW (I1) voltage. Do you have the fuel pump ballast resistor?

Yes. You should see voltage (B+) on those pins while cranking. D1_5: Fusible Link for Fuel Pump Relay. D2_4: Ignition Switch. D1_6: Fuel Pump side of the Fuel Pump Relay.

Using a voltmeter or 12vdc testlight (preferred) check for Battery_Voltage_(B+) on the following pins (use battery_negative terminal for ground): D1_5: B+ (Hot at all times) D2_4: B+ (Hot during KEY ON/CRANKING). D1_6: KEY ON (B+ (Hot for 2-3 seconds)) or CRANKING (B+ (Hot during CRANK)).

Keep us posted on this one.

Your DVOM (W2974) should serve you well with 12vdc stuff, but maybe not so good with 'turned on turn signals'. Your friend gave you good advice about using the circuit tester (aka testlight) for what I was trying to do with a DVOM. So, if that circuit tester blinked brightly like a turn signal (TEST 2) then vehicle and vehicle wiring has tested good. Seems to me, problem lies within the Instrument Cluster, even though it has also tested good. Check/replace BULB holder socket. How that for help.

photo @cruiser54 Note TPS with ECU and TCM connectors. Is yours like this one? If so, then you got the manual Engine Control Harness which would be blank at C101_C1, C101_C2 and C101_C3.

Did you swap out the Engine Control Harness when you went with the manual trans?

Auto or manual trans? If manual, do you have the 3pin and 4pin connector for the TPS circuit?

Trigger wheel radial runout is 0.016 inch (0.40mm) using a dial indicator on the inner surface. Check out page 77 or 2A-15

Take that air bonnet (aka ADAPTER, Air Intake) off at the throttle body and make sure you're not starving on air. Look/make sure the throttle plate is moving.

If you got a 4.0L: Using a voltmeter or 12vdc testlight (preferred) check for Battery_Voltage_(B+) on the following pins (use battery_negative terminal for ground): D1_5: B+ (Hot at all times) D2_4: B+ (Hot during KEY ON/CRANKING). D1_6: KEY ON (B+ (Hot for 2-3 seconds)) or CRANKING (B+ (Hot during CRANK)).

Disconnect C156. Disconnect C203. Check for continuity between these two points (GRY/BLK) on the IP Harness side. I don't understand this testing. Connect C156. With C203 disconnected measure for voltage between C203_10(BLK) and C203_11(GRY/BLK) with KEY ON and Left Turn Signal ON. Looking for 12vdc_0vdc_12vdc_ect_ect. Try and select a 20vdc range on your DVOM. In other words, auto ranging OFF.

This is what makes me think we have a Voltage Drop. Plug/Unplug is a good thing for all these connectors. Voltmeters are not the best tool for finding Voltage Drops. A testlight will tax the circuit (dimly lit), if voltage drop exist on the circuit.

Looks like we could be chasing a Voltage Drop (VD). You need a simple 12vdc test light or just make one. Example: Test Light Find and disconnect C118. Make sure you have good contact between each of the pins. C118_4 - BLK C118_5 - RED (PNK) C118_9 - BLK/WHT

Thanks