Ωhm

Your dropping voltage somewhere. Bypass (jumper) fuel pump ballast resistor. Take voltage reading at fuel pump harness connector again. Swap relays around. Take voltage reading at fuel pump harness connector again.

Yes that. What is battery voltage?

Do this voltage reading again but this time disconnect fuel pump motor.

They had special build in features. 10 minute timeout, 5 minute timeout after that. I wonder if there could be some kind of secondary use (ex: Fans, Lighting etc).

Does valve cover front vent line go to air box?

Isn't there a fixed orifice (2.6mm) on that line?

Thanks on that. Just curious.

Are XJs defogger relay (timed)/switch (3 pole) still available?

Purpose of the "B+ Latch Relay" (aka "Power Latch Relay") is to reset engine idle speed for next ENGINE START. Relay stays LATCHED (activated) for 2-4 seconds after KEY OFF supplying voltage to ECU allowing ECU to reset idle speed.

"B+" is just my quick way of typing 'voltage from the battery positive terminal'. But I see what you mean since the vehicle is equipped with a "B+ Latch Relay". I can be confusing at times.

Got my T-shirt and magnet today. I like the Tee, same as @JMO413, looks good. The magnet is a little dull in the color (red/blue), could/should have been a little more vibrant. But none the less I'm pleased with both. For being bootlegged items, this stuff is pretty cool. Got my eye on the coffee cup next. I wonder who originally requested this stuff.

True. My reference is to a prototype vehicle. It was a one of a kind only.

Once you determine which Relay is the Fuel Pump Relay, remove it and jumper Pin_1 to Pin_4 on the relay block. This will supply B+ to the Fuel Pump at all times. No need for KEY ON.

My first sight/drive of the 4.0L was in a SJ. Engine was non-regulated and ran very strong. Time wise I'll say 1986.

Even with that connector disconnected you still should have LOW speed on the Blower Motor.

Good eye @Pete M. Can't tell how bad it is, but definitely seen some heat.

I see it tight in there. I'm using the 88 Electrical Manual and looking at your past postings, you got 89. I'm assuming (again) they are the same. But I don't see C236. If you can't find it or its not on the 89 vehicles, we can try testing at C235 (brown 5_pin).

First off I assume your vehicle has AC. With KEY ON and D236 disconnected, D236_D should have Battery voltage (B+) on that pin. If it does then we can bypass the AC Mode Select Switch by using a jumper wire between D236_D and D236_E to see if Blower Motor spins.

At the AC Mode Select Switch disconnect C236. Make sure you have B+ on pin C236_D. If yes, jumper C236_D to C236_E. See if Blower Motor works.

Check the color code on the wire that goes to Pin_4 cavities. This will let you know which relay is the Fuel Pump relay and which relay is the B+ Latch relay. ORN=Orange PNK=Pink

I'm ready. Lets do it.

Remove both relays and look at the relay blocks. Check Pin_4 on the relay blocks. The one with ORN in it, will be the Fuel Pump Relay. The one with PNK in it, will be the B+ Latch Relay.

^^concur^^, but I did buy a t-shirt & magnet.

New to me site. Could be a rerun for others. AMC RENIX (ADULT APPAREL - KIDS APPAREL - HOME GOODS - CASES & STICKERS)

Try this. Let me know if it worked or not. Jeep_Renix_Fuel_Injection_manual.pdf