95 E300D: Poor fuel economy, hope it's not a vacuum leak. - Page 3 - PeachParts Mercedes-Benz Forum

Bio300TDTdriver · #31 07-02-2008, 11:53 PM

Quote:

Originally Posted by Kaiser Soze

Yep. AC blows, but not cold. The thing is, I thought that if I jumped the two pins on the blue coolant sensor, the fans would run constantly, yet they do not. I suppose it could be something else. Anyway, I'm working on an other coolant sensor, so if that doesn't work, I'll check the ovp wiring next. Does anyone know where to get a new plug (126 540 30 81) for the 4 pin coolant sensor (008 542 32 17, listed as water temp. sensor)? If not, is it possible to break it open in a way that it is still usable? The wiring is degrading all the way to the plug.

You need to connect a wire to the 2 sockets you pulled off the pins, not the pins themselves. The sensor is just a switch. So by jumping the wires with a short piece of wire you are removing the switch. Does that make sense? You are talking about the one just behind the upper radiator hose, correct?

Kaiser Soze · #32 07-03-2008, 12:53 AM

I had the sockets connected to the pins with a wire wrapped around them at the bottom. So unless the the pins were no longer able to conduct electricity, it should have closed the circuit. Sorry, but for whatever reason, I forgot to mention that it was still plugged in. I tried it again, and after spinning the fans around with my hands, I got one of them to work. Or it just takes more time to kick in than I thought.

Quote:

Originally Posted by Bio300TDTdriver

You are talking about the one just behind the upper radiator hose, correct?

That is correct.

Kaiser Soze · #33 07-07-2008, 01:05 PM

Right now I'm trying to test the ELR relay (N8) with some very helpful documentation sent to me by Phil. As you can see from the picture, it is asking me to test the resistance between connection 10 and 12 (under Tester/Test Connection). The problem I'm having is that neither the pins nor their proper connectors are labeled as such. Instead, it's labeled: 31, 15, EL+, GM-, GM+, TF, TD, and DI. Does anyone know where 10 and 12 should be? For that matter, does anyone know what connections any of these numbers on the attached page are referring to? Is there a pattern or something by which I can determine the correct connections? If this helps, L3 is the speed sensor, N8 is the ELR relay, and N37/3 is the ARF/variable intake manifold system control unit (EGR relay I think).

Kaiser Soze · #34 07-12-2008, 12:10 AM

Ok, I've figured out my last post. They wanted me to test the plugs that the relay connects to, not the pins on the relay itself. Knowing that my engine speed sensor (L3) works fine, I hooked up the multimeter and by testing each plug I found that 10 = GM+ and 12 = GM-. I got 584 ohms between the two, which looks to be barely within the +/-10% of 527 for Beru.

In further testing, I found that something was wrong with the ac compressor cutoff microswitch. It was pretty dirty, so I cleaned it off and reattached it which got it down to the correct resistance at CTP and WOT. Now my resonance flaps seem to be working better and my EGR valve works again too. Unfortunately, I still can't get the first intake flap to work. One thing I haven't eliminated is the altitude sensor. Actually, I don't even know if I have one. I can't find it for my model on EPC net, ebay, fastlane or any of the part shops I've visited. If my car does have one, does anyone know where it would be? Aside from that, the other two possibilities include the ELR relay and the EGR relay, which they call "ARF/variable intake manifold system control unit." Does anyone know of a procedure to test those units? If not, would it be reasonable to conclude that it's either of those relays since I've eliminated, the ovp, the engine speed sensor, altitude sensor, and all associated wiring? Those are all the listed possible causes of having incorrect supply voltage to the Vacuum control flap (Y28). (reference attached pictuer)