So I bought this dixco 11,000 rpm tach with shift light last week and installed it in my car (has stock points distributor) and it wouldn't work. So thinking I bought a bad tach i tried it in my el camino (HEI distributor) which has an old sun super tach in it and the wires have quick connect plugs on them. So I stuck the wires in the plugs and it worked perfectly, needle moved, shift light worked and back light worked. Put it in my other car again and nothing. I have black to ground, red to fuse box battery, yellow to lights, and green to coil negative. I know the ground is good because the light would turn on when I turned the lights on. So could my coil be bad or am I putting the green wire in the wrong spot? Or could it be something with my fuse box because the wires are going to the same spots in both cars.
If your motor runs, the coil is OK. I'd check the tach ground to engine ground with an ohm meter. You may have to add a ground wire from engine to body.
Thanks for the info. I'm going to mess around with it today but I don't believe I have any grounds straps coming off the motor to the body. Might have to add one.
If your engine has rubber mounts you may need to add a ground strap or 2. Sounds like you are wiring correct. You may find needed wiring directions or helpful wiring instructions on MSD's website. They have a ton of info for all of their electronics which incorporate a lot of stock components, so you may see something helpful there. I've used it many times.
check the red/power wire , you said that the light comes on when you taurn the lights on . This confirms the ground and the light wire . so all that is left is the power wire and the trigger/tach wire . Brian
So I just took a quick glance at it and I have no ground straps running from the motor except for the negative battery cable which has a small wire coming off of it going to the fender. I am assuming that this is probably not enough? Going to check the power soon after I get some wire to extend all the tach wires to make it easier to work with. And if the rubber mounts your talking about are motor mounts my car has the ones from the factory.
Or what it is connected to. It should be connected to something like a pin in the fuse block that comes on with the ignition . Your power source may not have power.
Sorry I haven't updated this in a while but I messed around with it today again and it still won't work. I know the ground and light wire are good. I put a test light on the switch ignition source (red wire) and the light turned on when I turned the key on so I know that's good. All that's left is the trigger wire. I put a test light on the coil and it lit up on both the positive and negative side of coil. Not sure if that's correct but I think I'll try a ground strap from the motor to the body and see if that works. Otherwise I have no clue.
Read the directions carefully......it worked on your other car, so, by process of elimination, your hooking it up wrong..... you should have a ground(green), a hot(black), one for your internal light that hooks to your other lamp(Yellow), and a wire that hooks to your coil( usually red). Any other wires? If your El Camino had HEI, you said you were hooking it to your coil, on the other car.....NOT HEI? Might be your problem..........
There are no directions for it, it's an old tach I found on craigslist and I haven't seen/found any other ones like it. I have it wired exactly like my other car except that one has an hei distributor. So maybe it only works on hei's? Idk but I know I have it wired correctly and all the connections are good with a test light. Just can't figure out why the need won't move.
you should have a ground(green), a hot(black), one for your internal light that hooks to your other lamp(Yellow), and a wire that hooks to your coil( usually red). Any other wires? If your El Camino had HEI, you said you were hooking it to your coil, on the other car.....NOT HEI? Might be your problem..........[/QUOTE] That's completely wrong cause on this tach and all the other tach's I have had the wiring is green-coil, black-ground, yellow-lights and red-hot. And yes my chevelle is stock points so I think that might be the problem.
Is the tach itself grounded when hooked to the points car? Or is it just hanging in space while you're testing it?
Yes I have the ground hooked up. I have the black ground going to one of the bolts on the emergency brake pedal. I have the yellow wire going to the light plug on the fuse box. I know those two are good as the back light on the tach comes on when I turn on the headlights. I have the red going to a switched ignition plug on the fuse box. I know that works cause I tested it with a test light and it turns on and off when I turn the ignition on and off. And the green wire is going to the negative side of the coil. Is the negative side of the coil suppose to light up with a test light on it? I've never done it before but for some reason it only makes sense to me that the positive side of the coil should only light up with a test light. Both the negative and positive side of coil light up. But maybe that's correct? Idk.
So I hooked the green wire up to the positive side of the coil today and it works but the tach seems kind of sluggish when you rev it up. In my other car it would go up really fast when revved. My question is why would it work on the positive side and will it hurt the tach?
the only thing i can say is it should be {green}hooked up to the neg.side of the coil.did you try hooking the black{ground}up to the engine?if it worked in anouther car than maybe the engine ground isnt good enough.
What kind of car are you trying this on? Can we assume some GM 60s-early 70s? If so you're reading through the 6v side of the coil by virtue of the resistance wire. Might be the "lazyness" you're getting. It should work on the neg side and you are hooking it up right according to most tach manufacturers. Why you're not getting a reading from the neg, don't know yet. Got a tach and dwell meter? Qualify it. Try to take an RPM reading with it. Also, take the back loose and see if it's been "clipped" for a 6 or 4 cyl. Some tachs have a wire to clip for less than 8cyls.
I hooked it up on my 1970 chevelle. I think the problem is that I have no ground straps coming off of the engine. The only one I have is coming off the negative cable by the battery and going to the fender. However I don't quite understand how that would make the tach work correctly. I don't believe the car came with any ground straps as I can't find anywhere where they would go on the firewall. As for the wires in the tach they haven't been clipped so it's still on the 8 cylinder setting.
The wire that goes to the distributor should be on the negative side of the coil. The + terminal on the coil comes from the ignition switch. If these wires are reversed the coil will still produce a spark but will be weaker than normal. The points in the distributor are the ground for the ignition system when they are closed. It sounds like your coil is hooked up reversed.
Move the black ground to the engine, not the brake pedal. That will work for the lights as it's the same ground, but it wont make the tach work. You can take a jumper from the present ground point to the engine, and I bet it works fine.
Well today I took a good look at it and turned out the person who owned the car before me wired the coil backwards. Switched the positive wires with the negative side wires and now the tach works on the negative side like it should. Moved the ground to one of the valve cover bolts. Tach seems to still be a little sluggish though in response to the throttle compared to the other car.
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