4 cyl. tach conversion

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Professor Fate

Professor Fate

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Not an A body, but I've been converting the gauge panel from an '88 Daytona to fit my '88 Dakota- full gauge instrumentation as opposed to the Dak's idiot lights, buzzers and blank spaces. The gauges and speedometer present no problems, but I also want to use the tach. I remember there being a particular resistor rating to run in the signal wire to make the tach read V8 rpms instead of 4 cyl., but I'm having issues finding the value needed (Google hasn't been any help, either). I know I could just wire in a potentiometer in the 1K range and adjust it using a hand held tach, but it'd be nice to just solder in a resistor and be done. Does anyone recall what the value is?
 
My experience with a 1988 Omni turbo. Tach needle was driven by a stepping motor. That can been determined if needle stores RPM, when engine is turned off. I made my own ECU with direct fire ignition. It was waste fire,which so I needed to generate tach drive signal with ecu, and switched inductor to generate 60V pulse per ignition event. It worked great.V8 tach may be easier solution, unless you can design a high voltage flip-flop to divide V8 triggers by 2.
 
Look for a 90 up Dakota V8 in junkyard, and remove its tachometer drive board from the instrument cluster. Then snap it in place of your 88 daytona tach drive board. Problem solved. The tachometer itself should run to the drive boards cal setting. I know the 1990-1991 daytona 4 cylinder tach drive boards would work on the 1988 4 cylinder cluster. The 1990 up were offered with s V6 as well. I am betting the truck V6 and car V6 are the same PN drive board. Chrysler made the same dakota cluster for all 3 configured trucks, and used the appropriate drive board to run the tach. 1990 V8 has the same exact board but they are calibrated for either 4 cylinder, V6, or V8. This is why I say get one off a V8 truck around 1990-1991. Heck, get a couple. These tend to go bad.
 
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Also if your wanting actual gages on your dakota, why not just buy a Dakota instrument cluster that has the full gages, like from an SLT with a V8 tach board. Thread in the proper sender units on the engine to make em read right, and plug it right in. Why reinvent the wheel.
 
I have a junkyard near me that's full of V8 daks. Several SLTs with full gage instrument clusters. If your interested I can grab one.
 
moparmat2000 said:
Also if your wanting actual gages on your dakota, why not just buy a Dakota instrument cluster that has the full gages, like from an SLT with a V8 tach board. Thread in the proper sender units on the engine to make em read right, and plug it right in. Why reinvent the wheel.
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That would be easier, but I've been looking for a while and haven't found any locally; not many left in the boneyards around here and I'm not paying Ebay prices. So just trying to use what I already have. It's actually a pretty close match.
 
Ok. I could probably get one for $50. I mean that's pretty cheap. Maybe grab an extra tach drive board
 
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