Tach install goes BAD
https://www.hdforums.com/m_1489588/tm.htm
Here's follow up:
So Tach works BUT might have killed the Speedo. Took the bike for a test-drive and had no odometer and no speedo. I can push trip button and odometer reading shows for total mileage on bike but no trips are displayed.
According to the Electric Diagnostic manual you can do a speedo check by pushing in the trip reset, turning the ignition switch ON then let go of trip button. Make sure kill switch in on RUN. For me nothing happens. Next step: It says to then push trip button with ignition off. If the odometer displays replace speedometer.
Not sure what happened. I had the whole speedo/dash off the bike while I ran wires and spliced in to everthing you need to install tach.
Brief run down on what I did. My bike is a ‘05 Night train: carbed. The tach is an Autometer mounted along with my HD oil pressure gauge on a rocker bracket
As I read here on the forum and in the directions I borrowed for installing a HD tach I got power for by tapping into the speedo’s power and ground, which was the orange wire with WHITE stripe and solid black wire.
The tough part for me is the tach leads. According to both HD tach instructions, wrench at the dealer and guys here on the forum you can use the empty #3 slot in the plug for the speedo to get the tach signal. For me that was a no- go. Would not work. No tach signal. Had I had EFI and not carbed that should have worked. Autometer’s instructions imply the same. I pulled out the wire I made for the #3 slot in plug and left it as it was when I started.
Went to plan B and just spliced into the two coil wires that plug into the ICM under the seat. ( FYI: the autometer tach has TWO signal wires so I just spliced each one to a coil wire and left the tach setting to stock one pulse- You have a choice of 1 pulse or 2 pulse) All connections are soldered and “shrink tubed†so all connections are good. As I said before tach works great.
So now it’s off to dealer to take it without any lube and have the speedo changed out, Unless ( I hope) they have other tests that will prove me wrong.

"According to the Electric Diagnostic manual you can do a speedo check by pushing in the trip reset, turning the ignition switch ON then let go of trip button. Make sure kill switch in on RUN. For me nothing happens. Next step: It says to then push trip button with ignition off. If the odometer displays go to next step.
NEXT STEP; TURN ON INGNITION AND IF ODOMETER DOES NOT SHOW REPLACE SPEEDO.
I'm just glad it did not go that route
Here's all info
I got it ( tach + Bracket) from Jpcycles.com
Tach (2"-5/8) is p/n 570-004 $214.00
Bracket p/n 740-951 $268.99
I had already had the rocker mounted oil pressure gauge from HD.
New Bracket was meant for an Autometer oil pressure gauge but the HD one fit just fine. I just added a piece of tape around gauge for snugger fit. Both gauges are held into bracket by allen set screws on rocker side.
Also if you wire in tach signal leads to coil wires as I did, tach stays on
one pulse ( factory setting)





