How Do you test Tach harness??

[Speedfreak]

First it never worked.   Just got a rebuilt Tic Toc Tach , but when I put the cluster in neither works.  Have to assume the unit is good, so wiring must be bad.  What is the procedure to test the wiring?  Clock cable should just show 12 volts, but how about the tach, what kind of signal should I be getting?  How do I trouble shoot the system? Maybe I just have the wrong wire connected?  One has a push on terminal, that i am sure is correct. Then a spade terminal on the housing, then a pigtail harness is the other.  Maybe I have the 2 wires crossed?  

[tan top]

what year ?

[Speedfreak]

what year ?

Sorry, it is a 69.

[Just 6T9 CHGR]

http://www.dodgecharger.com/forum/index.php/topic,15171.0.html

Remember the housing must be grounded by having the cluster fully installed in the dash or by a jumper wire if testing the tach seperately

[Speedfreak]

http://www.dodgecharger.com/forum/index.php/topic,15171.0.html

Remember the housing must be grounded by having the cluster fully installed in the dash or by a jumper wire if testing the tach seperately

Was not fully installed, still pulled forward, but my other gauges worked, wipers worked, turn signals etc.  May have been touching  slightly, but not fully installed.  

If I run a ground from the dash frame to the cluster and still not working, how do I check to make sure it is getting a signal from the coil?  Both the push on connector on the tach and the pigtail should be 12 Volts, right?  Just need to know how to check the coil wire.

This is exactly what mine looks like, the post has a push on terminal (12v), the spade on the back is coil?, the pigtail is clock(12v)   Right or wrong?

[Just 6T9 CHGR]

Yes...the tach MUST be grounded.

The bare LONG post is switched 12v+
The spade is for the (-) negative side of the coil
The pigtail is for the clock

[Speedfreak]

OK, that question is out of the way.  Now how do I test the coil wire plug for a signal?  Test light for anything, or continuity tester just to make sure there is no break?  What is the accepted way?

[Just 6T9 CHGR]

Just use a continuity tester....make sure its on the (-) side of the coil

[Speedfreak]

OK, after all the testing, bottom line, the unit does not work.  Checked wiring, coil wire is good, all plugs that should have voltage do.  Even bench tested it by hooking up all the leads directly by my engine compartment, pos, neg and coil,  no tic toc, no tach.   Also brought it to a local electrical shop, they could not test the tach, but hooked up the clock, they got nothing also. Looks like their work was not their best, this is not the first issue with their work,  this is wasting my time, should be out driving, instead I have to send it back and wait ...  

Has anyone else had similar problems with a rebuilt TTT