Electronics/eberspacher question

[pcatterall]

A guy is writing to me with eberspacher problems. he has a D1L (the one with a relay) he has at last got it working and swears that the wiring is exactly as per the diagram and good connections all round.
problem is that it will only work when he connects his digital multimeter to the negative side of the glow plug and battery neg! As soon as he removes the meter it stops. He tried replacing the meter with a lead and nothing happens.
I guess we could tell him just to wire in his meter as a switch but that seems a bit OTT.
How can his meter be reaching the parts that all other wires cant??

 

[Juggler7823]

I'm not sure which relay version of the d1l you refer to but there is some confusion about that with the single black box controller with an on/ff switch and round thermostat knob. There does not seem to be connections for this controller in the instruction book. In fact you wire the controller as if it was the round knob version which is in the instructions booklet. Sorry I do not have the connections to hand.

 

[pcatterall]

Yes thanks, we had the same problem and in the end he has wired it as you say. I just cannot understand how his voltmeter link has managed to get it going, wherase trying the same link with a lead does nothing. He seems to have some sort of earthing problem though.
Thanks again
Peter

 

[bobgosling]

A very long timesince I did any electronics but it sounds like the meter is working in the same way a a charging light bulb in an alternator circuit. It has just enough resistance to pull the circuit down causing the voltage to take a different route ? Sorry, if I'm talking bow-locks but it may make you think outside the box /forums/images/graemlins/ooo.gif

 

[FlorealIII]

There is no current flowing through a voltmeter and so I don't think you can compare it with a light bulb . There must be another reason , remember that digital multimeters have a battery inside , mostly 9 volt .

 

[mikejames]

There is some current flowing through the meter but it will be nano-amps. Leakage from damp would cause a larger current to flow.

More likely is the pressure from the multimeter probe on the wiring is closing a broken connection. He should try simply pushing on the connection with a biro in the same manner as with the multimeter probe. Then replace the cracked component (glowplug ? )