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Author Topic: Gas Tacho / Revcounter Conversion to Diesel W terminal  (Read 188969 times)

Reply #150November 26, 2018, 10:36:36 pm

ORCoaster

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #150 on: November 26, 2018, 10:36:36 pm »
Do you need to modify the electronics on the board?  Or is that only apply to a gasser to diesel conversion?

Reply #151April 13, 2020, 09:20:23 pm

srgtlord

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #151 on: April 13, 2020, 09:20:23 pm »
I just ran across this youtube video. Apparently you can by a diesel tachometer for $23 on ebay. The video shows a vw mk2  with the gauge hooked up.  https://www.youtube.com/watch?v=XBhNItz8HAU


Reply #152April 16, 2020, 09:42:56 pm

ORCoaster

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #152 on: April 16, 2020, 09:42:56 pm »
Went to Car Lab and could not find this tach anywhere.  I wonder if it is a gasser and not for a diesel.


Reply #153April 22, 2021, 04:56:24 pm

absenth

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #153 on: April 22, 2021, 04:56:24 pm »

Reply #154September 01, 2023, 04:30:36 am

Gagarien

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #154 on: September 01, 2023, 04:30:36 am »
Hi Mr RabbitJockey, thank you for your time and effort, By following your guide I got the Tach to work on my AAZ pickup installation, I used the resistors I had, and although not horrible off it is working only need to do the cal now.

Cheers

this is to convert a cabriolet motometer tachometer into a vw diesel tachometer

board with tracks drawn on to it (i'll add proper parts lables soon):



Original diagram i drew to make it easier for me to understand to convert it:



and i took my diagram and used to figure out how to make the cabby board match this:



directions

1. replace d1 with a jumper wire
2. remove r2 and r3
3. replace r1 with a 15k ohm resistor (you can use the original r7 for this)
4. replace r4 with 191 ohm resistor (i used 2 100 ohm in series)
5. replace r7 with 10k ohm resistor
6. replace c1 with a 10nF capacitor
7. replace c2 with a 47nF(.047uF) capacitor
8. replace c3 with a 47uF capacitor (i used electrolytic how ever i just realized that i only removed c3 and the tach still worked when i tested it, so i am going to guess it is only there for filtering because it goes from the signal input to ground, replace it anyway just to be sure)
9. replace c4 with a 3.3uF capacitor (i used 3 10uF capacitors in series)
10.  calibrate!!!! i usually put the pot on the end of a long wire that way i can fully install the cluster and then adjust the tachometer as i drive, and then when i am finished tuck the wire away neatly behind one of the dash blanks
11.  enjoy your accurate fully functioning factory appearing diesel tachometer

Reply #155September 02, 2023, 12:03:45 am

ORCoaster

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #155 on: September 02, 2023, 12:03:45 am »
I use this all the time.  I try to find those old clusters on CL and convert them to work with a diesel.  I think I still have two to do.  Not a real big priority but If I just want to goof off at the workbench they are there calling my name. 


Reply #156September 08, 2023, 09:56:56 am

RabbitJockey

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #156 on: September 08, 2023, 09:56:56 am »
hello i am glad to hear it, I can't believe how long its been since I did that conversion. I used to convert them and sell them but I never charged enough to make it worthwhile. Now i think it's easier and cheaper to just add the glowplug led and then use a dakota digital adapter with the unmodified gas tach. But for a DIY person at home with some soldering skills converting the tach yourself is a great option and only costs a few pennies and your time.
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Reply #157September 08, 2023, 10:54:32 pm

ORCoaster

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Re: Gas Tacho / Revcounter Conversion to Diesel W terminal
« Reply #157 on: September 08, 2023, 10:54:32 pm »
My take is that you end up with a VDO/ VW factory-looking unit when you are done.  Toss that clock outta there.  You probably have a digital one on the radio or phone display anyway.


 

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