Rocinante33
Contributing Partner
My tachometer stopped working the other day. So far, my troubleshooting hasn't revealed the cause, but I could troubleshoot much more efficiently if it was an old gas burner I was dealing with....its a Universal M25. The tach receives it's signal from the alternator.
I recently upgraded my alternator to a new 90 amp, and the tach did work for about 45 minutes of engine time. Now, at idle, it shows ~500 rpm & drops to ~ 200 as I rev the engine up. So, possible causes are quite numerous; 1. I could have caused a problem with my installation, 2. old, tired wiring or connections could have failed, 3. Tach itself could have failed.
When I investigate, I get ~6-7 volts DC or AC measured at the alt. output with the engine running - it varies slightly when reving the engine. The same at the tach, so I think that wire is OK. The alt is producing 13 - 14.5 volts from the DC output terminal, so it appears to be working OK.
Can anybody advise me on troubleshooting this problem?
Thanks in advance,
Keith
I recently upgraded my alternator to a new 90 amp, and the tach did work for about 45 minutes of engine time. Now, at idle, it shows ~500 rpm & drops to ~ 200 as I rev the engine up. So, possible causes are quite numerous; 1. I could have caused a problem with my installation, 2. old, tired wiring or connections could have failed, 3. Tach itself could have failed.
When I investigate, I get ~6-7 volts DC or AC measured at the alt. output with the engine running - it varies slightly when reving the engine. The same at the tach, so I think that wire is OK. The alt is producing 13 - 14.5 volts from the DC output terminal, so it appears to be working OK.
Can anybody advise me on troubleshooting this problem?
Thanks in advance,
Keith