Tachometer(VDO) Problems on Volvo Penta

Reflection

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Can anyone help me please with where to get the setup instructions/manual for Tachometer head for the above, VDO Model N02070009 or Volvo number 873660.
Also does anyone have an idea how to check if the problem lies with the Tacho sensor or the head. Tacho sensor seems to be an inductive one and operates off the fuel pump drive gear. When I check the resistance I am getting a reading of about1000 Ohms.
Problem manifests itself in that tacho does not read at all, hours meter displays hours but has stopped counting. However when Engine is started the hours display commences flashing.
Any help appreciated.
Rgds
Richard
 
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Tacho sensor seems to be an inductive one and operates off the fuel pump drive gear. When I check the resistance I am getting a reading of about1000 Ohms.
Problem manifests itself in that tacho does not read at all, hours meter displays hours but has stopped counting...

Switch your meter to Volts, run the engine, and see if you get a reading between the sensor output and earth, at both ends of the wire.
 
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Reflection

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Yep. did indeed and getting same reading which would indicate that the wiring is fine. Also disconnected both connectors, shorted one end and checked resistance from other end, read zero ohms so certain that problem is not cabling. Unfortunatly:-(
 

Reflection

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Hi Nigel,
A pair of wires run back from the sensor to the head add when I measure across them with the engine running I get about 2Volts rising to about 5Volt when revs are increased. Meter only shows a reading when swithced to AC. I'm presuming that is due to the "pulsing" nature of the signal.
Ta
R
 

Angele

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I believe that problems with the Volvo control panel are not uncommon, although usually it is just with the engine hours meter and not the rev counter too.

My engine hours counter stopped working 3 or 4 years ago.

You can usually bring it back to life by removing it from the boat and sticking it in your airing cupboard for a couple of weeks to dry off completely and then replace one board. Certainly, this work for a brief while for me. It is, however, at best a temporary solution.

I have learned to live without.

If your tacho also isn't working, then this may not work for you and you may have a bigger problem.
 
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I get about 2Volts rising to about 5Volt when revs are increased. Meter only shows a reading when swithced to AC. I'm presuming that is due to the "pulsing" nature of the signal..
I did suspect that you might need AC, but it depends on the meter. Assuming that the tachometer should be OK with 2V, then it looks like it is broken. I know that the hour meter on these is suspect, but I thought this was due to the LCD glass. I guess you could contact VDO and ask if these voltages are normal.
 

yoda

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Not sure if it helps but I have a VP 4 inch white EVC Tacho (vp 874 545) (4000 RPM) which I believe is unused and working. Welcome to try it for the cost of the postage.

Yoda
 

Reflection

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The damn things keep breaking. I've given up on the original volvo/vdo part and have gone for a newer VDO instrument ($99 compared to $280 in the U.S.)

Anyway... Here from my previous battles with the original equipment is the VDO instruction booklet... http://www.gilmoredist.com/howto_gu..._Sheets/VDOProgrammableTach_withHourmeter.pdf

Not sure if it helps but I have a VP 4 inch white EVC Tacho (vp 874 545) (4000 RPM) which I believe is unused and working. Welcome to try it for the cost of the postage.

Yoda

Tks for the offer Yoda, might get back to you on that. Will give fixing it another go first though.
Tks
R
 
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