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Seems we've lost are link to the 88 Electrical Manual. http://www.bteventures.com//mj1988electricalmanual.pdf Hope its just me with this problem. Yes I have a copy.

You want this for your front plate?

"88 MJ" is available (MI).

Who put your distributor in the vehicle? Distributor Indexing (crossfire) comes into play here. Check fuel pressure before replacing fuel pump.

Is that going to be your Downtown Detroit MJ?

At idle, timing is base timing. As you throttle down, timing is advanced and if Distributor Indexing is incorrect, crossfiring occurs. The trailing edge of the rotor must be at or just pulling away from the #1 tower. I notice cut lockdown tangs.

Double check Distributor Indexing.

Yeah, from manifold to MAP sensor.

Your symptom sounds like you still have a Distributor Indexing issue. Check MAP hose again.

Looks like C109. Engine Harness to Engine Control Harness. Next to RH shock tower.

Pull the HAZ/STOP fuse out. Determine if one terminal or the other terminal has 12vdc (testlight will also work) on it.

At 3:28 IP cluster view: What's that gauge in the lower right? Something for the diesel, turbo boost maybe. If so, was that electronically controlled?

I wonder if the Fuse Block was back-filled with all necessary fuses, regardless of what options were chosen by the customer.

Check your fusible links located on the starter relay. Check for open, bubbles or burnt links.

My mistake, you can't eliminate the dimmer control circuit. Always there when in PARK, LO BEAM or HI BEAM. Will not matter what position (rotated L or R) it's in.

Back to normal. Looks good.

You might want too keep your dimmer switch in the OFF position when using your PARK or LO BEAM's until you find the HI BEAM problem. Since you installed the Headlight Relay fix, it won't draw high current thru the Headlight Switch anymore, but it will trip the HI BEAM relay, unless dimmer is turn OFF.

Things always come out easier the second time around.

It ain't doing you no good the way it is. Gently, Gently. Try it on just one first.

That last photo could be area of concern. Also seem like bulb sockets, when locked in, have worn thru the foil. Check bulb sockets for good contact at terminals.

You are reading voltage that drops across the dimmer variable resistor (rheostat). 10.68vdc should be enough to light the lamps. With good voltage and good ground, problem may lie on the printed circuit foil on the back of the cluster. Look for any open circuits there.

What I was wondering is, when your LO BEAM's were ON did the Instrument Panel Lamps circuit power the HI BEAM circuit (melted C269_1) at the same time. Yes, your going to need/be a Harness Surgeon for this one. Instrument Panel Harness is difficult to deal with. Nothing easy here.

Should be good here. Check for voltage (12+) on the following pins: C203_1, C203_4, C203_9 and C203_16. Make sure Headlight Switch is ON and dimmer control is set to the brightest. Page 61 in the manual.

Do a search for "insert boot disk". Lots of information. May help.

Seems like that burned out HB indicator bulb hid the fact that your HI BEAM's were also ON with your LO BEAM's. Did oncoming traffic at night ever flash their lights at you? 88 Electrical Manual call the Instrument Panel Lamps circuit (WHT) and the HI BEAM circuit (ORG/BLK). Short is wherever those two wire run together within the Instrument Panel Harness.