Ωhm

Yes. If shorted to GND or shorted to a circuit with current draw (EX: lamps) could cause drain issue. C188_C should act the same, voltage wise, as C187_4. No need to look at it now. Wasn't this the pinout reading for C187?

Looks now like a voltage drop on C187_4. Should show the same reading on C188_C. If reading looks good, when measured, try wiggle testing the harness. Was this 'direct connect to battery' on C187_4 or on both C187_4&5?

Taken from his webpage. Photo 59 of 388.

This seems like the circuit between RADIO Fuse and C187_5 is a problem, yet original radio still worked. RADIO Fuse is powered by the IGN_SW_A (ACCY&RUN). Can you check C187_5 (KEY ON or ACCY) using a testlight. Using the testlight causes current to flow in the circuit. With HD_LP_SW OFF, C187_11 receives power from the RADIO Fuse thru RELAY(OFF). Once HD_LP_SW is ON, RELAY is picked (ON) then both C187_10&11 become DIMMER circuits. This would be for a factory radio.

Check pages 56 & 59. _mj1988electricalmanual_1.pdf

Does it act the same way with the HAZARD switched to ON?

Slow fuel leak at the Fuel Pressure Regulator (FPR).

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) D1_6: At KEY ON only (B+ (Hot for 2-3 seconds)). During CRANK Hot at all times. D2_4: B+ (Hot during KEY ON and Hot during CRANK).

Funny, I see it was there.

If you're looking to add vehicle information or any information on the bottom of each of your postings, go to Account Setting/Signature. Add your INFO and SAVE.

This is what we do.

Photo by Cruiser54

2.5L or 4.0L?

Long live Cruiser's tips. You'll be missed.

Make sure D2_4 stays HOT during KEY ON, CRANK and ENGINE RUNNING.

@Samohtgaoh Welcome to CC. Post your VIN in the Forums under 'Comanche Registry/1988'. Someone can get you your vehicle build sheet.

Make sure the bleeders aren't plug.

Fuel Flow test - page 6 Fuel Flow pg6.pdf

Works perfect. Those without WORD will need help.

Cruise Control ground, if equipped.

@Pete M I think you can post WORD.docs. Try it nothing to loss.

Start with the language used. Learn the history of the units involved. Meet the men and women named for these units. This helped me with perspective. Some great chapters on electricity. The World of Measurements

I think it had something to do with assembly. Ease of mounting to fastener. Quicker for the robots.

B1 & B2. I understand now.