87' om603 into 94' e320

[ontum]

Hello all,

Last week I took out an 1987 om603 (body in collision) and put it into a 1994 E320. I switched a lot of the wiring and vacuum lines over with the 603 along with the instrument cluster.

I am having problems locating a wiring diagram for the temperature gauge and tachometer. I swapped over the ecu with the 603, but can't figure out which wires I need to connect to get the tach and temp guage to work. The engine, ecu, and instrument cluster all came out of the 87' so I am hoping I can make both gauges work like stock. Any advice on how to make these work or a wiring diagram would be greatly appreciated.

Thank for the help in advance,
Craig

[auspumpen]

I assume you've perused page 12 here. I also have a complete 603 from a wrecked '87 300TD and spent hours dissecting the wiring harness to free up just the essentials required to operate the basic engine and peripheral functions. It's not modular at all. Aren't the '94 wiring systems CAN-Bus?



Here are the basic vacuum requirements to operate these engines, if needed.

[ontum]

Thank you for the quick reply. I don't recall when MBZ went to CAN communication. But the 87' does not correct? I am using all the wiring for the 87' ECU and engine from the 87". So I would assume I can bridge the gap between the engine, 87' ECU, and 87' instrument cluster. But maybe its more complicated than I thought.

I looked at page 12 of the link you sent and I can not seem to find where the ECU sends signals to the instrument cluster. Am I missing something? I don't recall where I got the information, but I thought the coolant temp and tach went through the ECU and then to the instrument cluster.

I have eliminated many of the vacuum lines line in your drawing, but the transmission shift very late and hard on its second shift. Maybe I didn't hook it up right. I ran a line from the vacuum pump to the top of the deal on the injection pump and then a line from the front lower part of that deal to the transmission. The transmission came with the 603 and shifted great before the transplant. Maybe you can point out where I went wrong here. Otherwise I may have to try and add the blue vacuum amplifier back on.

Thank you

[auspumpen]

I haven't studied the diagram in a while, but I believe the '87 connects back to the instrument cluster via the KLIMA relay. The '87 is not CAN, but I'm not familiar with how KLIMA or OVP are managed on those late-model cars. The early wiring harness ties the ECU in with both of those relays, at least tangentially.

You probably need to adjust both the trans. vac. modulator and bowden cable. The former adjusts the quality of the shifts (soft/hard), while the latter adjusts the timing of the up shifts (which RPM). There's no need for the blue flying saucer (BFS)--these were ditched on later OM60x cars

[ontum]

Thank you again for your response.
Interesting points on the modulator and bowden cable, but what confuses me is why the would be out of adjustment now, but were just fine last week in the 87' chassis. Does removing the blue vacuum amplifier change the vacuum enough to place the modulator and bowden cable our of adjustment?

Does anyone one have a wiring diagram or explanation for the instrument cluster on a 1987 300D and how to get the temp gauge and tach to work? It sounds like it is more complicated than it has to be.

Thanks,
Craig

[ontum]

I put the blue vacuum amp back in and now the transmission shifts as it should.

Can anyone verify how the instrument cluster gets the temperature signal?