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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Thu Feb 05, 2015 8:54 am Post subject: |
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Yep, the Digifant tachs work in some cases. Many times not and they are known to behave differently from other tachs. As an example, read this from instrument maker Dakota Digital, for one of their tach related products.
"Product not compatible with '86-91 VW Vanagon's and other similar models"
http://www.dakotadigital.com/index.cfm/page/ptype=...prd128.htm
Mark
Gauche1968 wrote: |
crazyvwvanman wrote: |
There is a known issue with the tach signal on Digifant 2.1 models. The tach made for that works but other tachs often don't. Even the tach from an earlier Digijet can act crazy if hooked to the Digifant. Likewise the factory tach for Digifant models is known to give problems when you are trying to use it with something other than a Digifant.
Mark
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Using two Digifant tachs on Digijet without any problems.... |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Posted: Fri Feb 06, 2015 4:46 pm Post subject: |
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Well....... I've the 86 Multivan with a BIG clock but no Tach...... So I guess I've got a Dog in this fight.......
I wrote to the company, referred them to this link and asked if they had feed back or suggestions......
Here is their response....... It's long...... Get a cup of coffee first!
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Hello.
I have read through the forum, and while I do not have a definitive answer (impossible to give without have the van, the tach, or both in my presence to inspect & test), I can give you some tips & information.
First, the suggestion of using a resistor in line was a good suggestion. The resistor simply acts like a bit of a filter to help filter out spikes in the signal which can cause a jumpy pointer. I do not know why the user is hesitant on trying a resistor, but opted to try a diode. A diode is a one way check valve and does nothing to clean up a dirty signal. Resistors are cheap, so I recommend to try it.
We also offer a tachometer filter which was originally designed for the same symptoms when used on both points & electric ignitions on the VW's with Bosch distributor. I was directly involved with the research on this. Where the simple resistor fix did not help the tachometer filter did. The filter is an Auto Meter model number 9116. It is imperative when wiring this, that it gets grounded to the engine.
When wiring the tachometer itself (regardless of what the previous tachometer acted like), I recommend grounding it to the engine as well. If the tachometer has a weak or insufficient ground, it is unable to cancel/filter out ignition noise as efficiently as it otherwise could.
I do also recommend connecting to the negative side of the coil which on my diagrams through Alldata for US Versions appears to be a green wire.
In order to check the tachometer, you may simply perform a temporary hook up on another vehicle to see how the tachometer reacts. Comparing to an unknown brand of tachometer is not always the best solution, and here is why. While tachometers all give you essentially the same information (how fast an engine is spinning), a tachometer can react very differently from the next based on its input circuitry, its meter type, level of dampening, and quality of components used to build the circuit. For example, Auto Meter tachometers are built with a fine balance with its level of dampening in order to have a tachometer that is performance orientated, and able to respond quickly, and to still try and dampen it enough to keep the pointer calm in low pulse frequency situations, or dirty ignition signal situations. With that said, if the previous tachometer had heavy dampening it can do a better job of filtering out what is happening, though would be a slow responding tachometer as a result.
I hope this has been helpful, and look forward to hearing the results.
Thank you
Cory
Tech/Service
Auto Meter Products
413 W Elm St.
Sycamore IL 60178
866-248-6357 _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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jsmiller Samba Member
Joined: June 09, 2011 Posts: 24 Location: South Australia
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Posted: Fri Feb 06, 2015 8:28 pm Post subject: |
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Thanks for that Dave!!
I had e-mailed Autometer as well so I got the same response from Cory!
I'm got going to order the signal filter he suggested and see what happens.
Thanks again Dave for your help! |
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jsmiller Samba Member
Joined: June 09, 2011 Posts: 24 Location: South Australia
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Posted: Sat Feb 21, 2015 3:46 am Post subject: |
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Ok folks success!! I wired the signal filter (Auto Meter model number 9116) in before the Tach as instructed and it WORKS!!!! Many thanks all
for the advice! |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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The Believer Samba Member
Joined: April 07, 2020 Posts: 11 Location: Hillsborough, New Hampshire
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Posted: Thu Sep 23, 2021 7:12 pm Post subject: Re: Aftermarket Tachometer |
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I have a 90 Syncro and tried to install the Autometer 2306 & 2300 Tachometer with the inline noise filter 9116 with no luck.
I tired numerous grounds and tach signal pickups. The 2300 with 9116 got a bouncy unreliable needle.
Would love to have just bolted in a stock cluster with tach if they weren't becoming increasingly rare and overpriced. |
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