Grant Baker Posted December 13, 2018 Report Share Posted December 13, 2018 Hi We have fitted a Monsoon to an AE86 Toyota Levin / Corrolla. The Tacho doesn't work on it. On other Toyotas / Lexus etc we have previously used a resistor on the tacho circuit board to make them work. Anybody know if the same is needed on these old AE86s? 1984 model... Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 14, 2018 Report Share Posted December 14, 2018 A distributor car from that era will have a "high level" tacho, originally designed to be driven from the -ve side of the coil (about a 50V spike). The 12V aux output signal wont be enough to trigger it. 3 common solutions; A commercial "Tacho adapter" device such as MSD 8920 or similar. I have used this one in a few different cars with good success: https://www.ebay.com/itm/142171581596 Modify the tacho - as you say this will often just be removing or replacing the input resistor. A DIY "Tacho adaptor" can be made with an old relay coil: https://www.haltech.com/wp-content/uploads/2013/07/Relay-Wiring-for-Tacho-Output1.pdf Quote Link to comment Share on other sites More sharing options...
Constant Posted February 15, 2019 Report Share Posted February 15, 2019 Open the tacho , find where the IG- goes and jumper the resistance between IG- and the corresponding pin on chip. After that its easy to calibrate , as 50% duty , and 1 multi Did that a week ago.. Quote Link to comment Share on other sites More sharing options...
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