I installed the Autometer 2 5/8” 5k diesel tac that senses off alternator in ‘15 and has worked well until recently when became intermittent. Contacted Autometer and they have it now checking whether problem is with tac or sensor. But what I discovered is there are 2 basic options from Autometer for diesel tacs. If you search for “diesel tachometer” on their site, should get 5 hits- one of which is the alternator sensor replacement BUT appears that only works with their diesel specific tac. If you search further they also make a tac sensor that has alternator sensor and converter box- think about $120. From description appears this set should allow using their regular (non-diesel) tac on diesel or any other non-distributor engine. Probably wouldn’t drive standard Ford in-dash tac but opens up options for other tac units- even non-Autometer units probably. But don’t expect the alternator sensor (about $40) to work with tax’s other than Autometer’s diesel units; appears these have internal circuits to read/convert the alternator sensor signal.
