Gauge cluster swap?
 

I have a 84 190D and some of the lights and clock are not working, I have a extra cluster from a newer 190. The newer one has the electric oil pressure gauge, the old one has the oil line going to the back of the cluster. Is there a way I can make the newer one work? Oil pressure is important to watch, so I need it. Thanks.

I would swap
 

the entire old left side instrument set into the new cluster package. That is assuming all of those instruments (oil pressure, ammeter and temp gauge) are working. Non-working lights are usually a simple bulb issue.

What Rocky Raccoon says. I swapped my fuel/temp/oil/economy cluster into a vastly better condition head, and now, my speedometer claims to go to 140 mph!! And, my clock and tach work!!

The clock can usually be repaired by replacing a few capacitors. Mine keeps perfect time.

Buy a box of these bulbs. I replaced all of them while I had my heater apart, and now everything lights up as it should!!

I replaced the bulbs and still does not work, I even took the cluster out a second time and hooked the bulbs up to a battery and they work. Put them back in and they dont work, its the right side bulbs, the left side works fine.

There are 2 larger 194-style bi-pin bulbs that light the cluster from above. Their sockets are installed on a small PCB installed above the speedometer. Clean the mating surface between the little socket and the PCB with a pencil eraser. Gently, of course.

I mention the 194 bulbs. Dont use these. They draw too much current. I **think** the right one is a 168.

Thanks, I will give that a try.