Rickster, if it revved up very briefly then you have eliminated the electromagnet as a possible cause- that is what it should do. Even though the test fuse blew, you got the test completed.

Follow Zulifar on the battery testing of the ELR connector as you need battery voltage from the ELR to this connector to operate the electromagnet.

I tested the current of mine and it pulled a maximum of 700ma so I thought 1 amp would cover it but it is a very inductive load.

With regards to the rule of applying voltage for no longer than 3 seconds to the electromagnet...I was relaying a quote, it was from Mercedes Benz engineers to which I usually do not beg to differ.

Please see attached paper.

Attached Thumbnails

 

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1995 E300 Diesel

Benedict, no need to explain yourself I trust you guys, I can tell you know what you are talking about.
I hope I can perform the other tests that need to be done, I just have a hard time identifying wires, connectors,relays, etc. I don't know what I am looking for.

to identify the ELR - remove the plastic curtain behind the battery, you will then see a few black cubical items.

the top of them will have some german language. and on them would be written verbatim

EGR (leave that alone - it controls the nasty EGR and also manifold flaps which boost engine torque)
klima (AC compressor - leave that alone)
ELR - (thats our business and we are going to work with it)

The ELR is what controls idle rpm.

its logic is that it only can raise rpm as required, so before we dig into the rpm raising bit, we need to make sure we can run the engine without "idle assist" meaning pull the two pin plug from the pump, the engine should be at about 500 rpm (look at the gauge) - If its not then we need to see why its not at 500 rpm, if its lower than 500 rpm does the engine have a leak in the fuel lines? or has it been set really really low from the idle set screw - its a locknut type screw near the ELR connector.

If its higher than 500 rpm, we have a problem, firstly make sure the alternator is working (a no load situation from a non-working alternator can cause high rpm) - once you have verified that

1 alternator is charging like it should
2 the engine is warmed up to normal temperature - above 80C line
3 there is nothing holding up the revs - like stuck or improper adjusted linkages.
4 engine revs freely like an OM606 should - it should rev pretty quick

adjust the pump idle screw to make the engine idle at 500 rpm - reconnect ELR and make sure the engine bumps idle speed to 650 rpm and stays there.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

If I understand what you are saying I need to go back to the pump and look for two wires (one red and one brown) and test the red one for voltage.If this is correct, where on the pump should I be looking for these wires?

Benedict provided a picture of the pump on post #23. where about on the pump should I be looking for the red and brown wires?

Rickster,

The connector is the one in which you have already unplugged to do the test on the electromagnet. If you can unplug it again and 1) see if your engine stays alive without the assistance of idle control and 2) test the voltage on the connector which you unplugged- you are testing the connector from the wiring harness not the connector on the actual IP.

Zulfiqar mentioned a brown and a red wire but I just had a look down through my crossover pipe and it looks like mine are solid red and red/white. I have a new harness. It's a bit hard to see as there is grime on my wiring. Anyhow you should have battery voltage at it and if not then we'll keep tracing.

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1995 E300 Diesel

the wires may be different (as my harness has an 07 date). The tests are the same as it has to work the idle speed control.

red wire should have solid battery voltage against body ground
other (brown or red/white etc) is the variable control wire and is traced back to the ELR cube socket pin 7)

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The differences between year runs dazzle me. The location of my ELR box is behind my battery also (RHD here) to the right of the EGR box but I compared it to my friends today, 6 months younger than mine, and his EGR and ELR box's are swapped around-exact same car.

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1995 E300 Diesel

Ok just finished testing 3.7 volts is what the tester reads.

3.7 V with key on at the pump connector red wire means that the Over voltage protection relay is not energizing or there is a break in the wire somewhere.

Its the silver relay with a plastic flip window on top - it should have two fuses in it. replace if burnt then check again. btw what else is not switching on in the car A/C? tach? gauges? If your relay fuses look good and also all fuses in the fuse box are copper type and good and other items are also not working in the car then the OVP maybe bad (its a part that fails with time)

You should see battery voltage at the pump connector if you dont then also check fuses in the fuse box. To verify that your OVP relay is working take your multimeter on DC scale and ground the black probe to the battery negative and stick the red probe into pin 16 of the diagnostic socket near the battery. This pin is a common wire shared to the ELR cube socket and also pump connector. It should show battery voltage with key on.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Fuses are all copper type and good.Every thing else is switching on, tach,gauges,etc.
Is there an easy way to remove the OVP cube,I can see it but there are other black cubes to the left of it that make it impossible to reach.Can I just pull those two out to gain access?
I will test pin 16 when I get home tonight.

if you have everything else working in the car and dont have voltage at the ELR connector on the pump then I think your engine wiring harness is damaged from somewhere.

Its got one plug that is also behind the battery curtain, and to access it you remove the curtain and remove the plastic carrier looking piece (slides out) and then you see the wiring connector - remove and test for continuity to the ELR plug at the pump.

also verify that you have battery voltage at pin 16 of the diagnosis port.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Ok I do have battery voltage at pin #16.
I tried to remove the plastic carrier looking piece behind the battery curtain and I was not able to get it out, does the whole thing slide out with relays attached?
There is one relay looking cube near the front and that slides up to remove it.

There is a plastic carrier piece that just slides upwards and out making for easy access to see and pull the connector for the engine wiring., the entire tray type piece is held by 2 or 3 sheet metal screws. The ELR relay type box is the one with the wording ELR on top of it. It should be the forward most one. If you flip it you will see some codes printed on the case, the code 15 is switched battery power (locate the hole that certain leg goes into on the socket) - this is the same wire that sends power to the connector on the pump, if you take a multimeter you should see battery voltage at that pin too when the ignition is switched on. If you find battery voltage then your wiring break is in the engine wiring harness.

This wire which goes to the pump connector is on pin 7 of the engine wiring connector (which is at the bottom of the tray type carrier thing which holds all the control units - and the pin numbers are printed on the connector itself)

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I will do this testing this weekend and let you know what I find.
Thanks for walking me though all of this!