Hello all, in need of some help..I bought a repo tach (plastic housing) sometime back from another board member..He replaced it with a original tach and kept the harness for his install..So my question is how do I wire this thing up (make a harness)? I will also need to know which wire goes where on the housing..There are 3 bolts on the rear 2 larger and 1 smaller (positive, trigger/dizzy and ground)..I will try to attach a pic of the tach (as I am sure this will be needed)..I appreciate any and all help with this lil project..Also the tach will be replacing a clock (doubt that matters, but thought I would say it in case)..The car is a 72 Skylark with a hei dizzy also..
I have the same tach. I installed it a long time ago. I know the trigger wire goes to the negative side of the coil. I think the 12volt is only for the lights so it needs to be wired into another light source so it works when you turn on your headlights. If your tach has the white ring around it you need to do the fix listed below while it is out otherwise you will see the light glowing from the sides. http://www.buickperformanceclub.com/ReproTachModifications.htm
Hey Brian, thanks for the help..The problem is this tach has no markings or ways to tell positive, trigger and ground..I believe the mod was already done to this 1 when I bought it (came with a original lense I used so it sits flush and new repo lense)..I'm hoping someone can remember which 1 is which (positive, trigger, ground) maybe from left to right so I can wire it up..Or a pic of 1 with the wires still attached would be great too..
Also Brian, from all I have read it seems 1 is a power source for the tach (has separate lights with wires), but I could be wrong and believe me it wouldn't be the 1st time lol..I have been thinking about biting the bullet and ordering a tach harness, but even with that without the tach having id marks I am not sure the directions will help..Seems my only problem is that like you everyone has installed theirs awhile ago and no memory of which 1 is which..Why couldn't the housing be marked like some others I seen with - (ground) and s (trigger) lol..
Still hoping someone has used this repo tach and knows whats-what with the connections for the rear plastic housing..Any help will be surely appreciated
I have the lights that come with the tach and the wiring that comes with them..Just not the spade connectors and wiring for the car..TTT
I do not think the wiring harness will work with that tach. I would just get under the hood and take 2 long pieces of wire and run one to the battery and one to the negative side of the coil and see if you can get it to work like that. If not switch the wires and see if that works. That way you would know which wire is which. I don't think you would hurt the tach if you hooked them up wrong. it just would not work.
Thanks Brian, that's what I was thinking of doing..Then I got a real lucky break from the original seller that remembered where he originally purchased the tach from..Ends up the place is only a 45 minute ride for me and tomorrow they are going to give me the wiring harness at no cost..I cant thank UticaGeoff enough for tracking all this info down since he bought it way back in 2010 from a ebay seller (also typed all the directions he had as they were too faded to scan and send)..Thanks again Brian:TU:
Would you be willing to post or PM me those typed directions by chance? I bought a second hand repro tach as well and don't have them. Think I've got it figured out, but wouldn't mind reading over them once to be sure.
Install your new tach in place of your clock or block off plate using appropriate service manuals as necessary. Remove the wiring harness from the plastic bag and install this harness to the rear of the tach. The plastic connector is polarized to prevent improper installation. Plug the orange or red wire with the black plastic connector (part of the above mentioned harness) into the fuse panel opening marked "ign" or connect it to an ignition controlled wire under your car's dash. The brown or gray wire with the metal ring terminal (part of the above mentioned harness) passes through the firewall and connects to the negative terminal of the coil, or the tach port of an HEI. If your new tach is supplied with a lighting harness, use the included blue plastic connector (from the bag that you removed from the wiring harness) to connect that tach light harness to your car's under dash harness. The wire leading to the light on your radio or heater control (both usually gray) is a good place to make this connection. The black wire, which is part of the light harness, grounds the mechanism and the lamps, and is connected to a good ground under the dash. Different years or applications, such as Nova, require different grounding procedures. [End of Instructions]
Well shoot, it no longer applied to me at "remove the wiring harness from the plastic bag" as I don't have one. Guess I'll just wing it freestyle... And Geoff, that's a lot of one finger typing!! Haha
Maybe Bill can get one for you when he goes to pick up his. As for my typing, 38 years ago, my fingers were much longer - they just have wore down over the years, especially since the pc was invented. When I started working, we only had typewriters, and I had a manual one at that! UticaGeoff
Ok, just got home after picking up the harness for my favorite price of FREE (Steve and his buddy even refused the $20 I offered for beers)..So I would like to give a shout out to GM Sport Salvage as they were great to deal with..Now my tach story isn't quit finished yet as they pointed out the lil dual spade connector must have been kept for Geoff's install along with the wiring harness..So now all I need to do is find that lil thing-a-ma-jig (I know there is a real name, but damn if I know) and pop the tach open to attach the wires back to the thing-a-ma-jig.Plug the harness and all should be good to go..I will take a pic of the harness for you Shawn as it looks simple enough to make 1 up..If not I got in touch with Gary (Shaggyfinisher on the board) and he may have 1 for sale..I found it when searching for how to's on installing a repo tach..
Sounds good Angelo, I'll see what you post and go from there. Thanks for the input, you've gone from the helped to the helper!! Haha
No problem Shawn, that's what makes this forum and hobby enjoyable:beer (also hope this may help some others as well)
