[Tyler1970FB]

Here is the scoop... My instrument cluster does not work. I installed a new circuit board, New voltage regulator, and checked the ground wire. All of the lights work, but the fuel, oil, temp, and volt gagues do not work at all. What else can I do? Also does anyone have the layout for where the bulbs are to be placed in the instrument cluster? Please help me before I have to take the car into a shop.

[Acooljt]

The slots for the bulbs are pretty noticeable because the bulbs only go into one hole. You can't miss em.

You said you checked all grounds, and on the assumption that you're correct, I'd say there has to be a power problem then. I'd look to make sure that you've got voltage where you're suppose to. I've never thoroughly examined the wiring of any of the classic Stangs, but I do have an extensive electronics background, and I'm guessing that there has to be a wire running from somewhere on your ignition(my guess is right at the key) that gives power to your cluster so that it turns on when you turn the key on.

[Veronica]

Hello.On something like that I think that I'd just start from scratch and assume nothing.First I'd run a wire from the end of the water temp sending unit wire to a suitable ground and turn the key to the on position .If the gauge pegs that means that you have a bad sending unit.I have seen plenty of cars that had all three sending units not working and the poor guy had just assumed that the problem was behind the dash.If the gauge doesn't move then you need to check the continuity of the sending unit wire.How I do that is with a flashlight battery and a volt meter.First check what the battery is actually putting out.Then run a wire from the positive side of the battery to the red/white wire that's hooked to the back of the gauge(easier to do if you disconnect the wire from the gauge )Put the positive lead of your volt meter to the sending unit end of the red/white wire and the negative lead of the volt meter to the negative end of the battery.You should get pretty much the same reading like that that you got when you checked the battery output.If the reading is zero or almost zero then the wire is bad.If the wire is ok then you need to check the wireing of the instrument cluster voltage regulator.There is a wire that supplies power to it that comes from the ignition switch.It will be the one that isn't going to the gauges.Unhook it and check to see if it's actually supplying power by unhooking it from the regulator,placing the positive lead of your volt meter on it and the negative lead of the meter to a suitable ground and turn the key to the on position.It should be supplying about 9 volts.If nothing,there is your culprit.On some cars that wire is very similar,after thirty plus years, to the wire that plugs onto the ground wire tab at the attaching screw of the regulator.Check that wire also and see if it's hot.If yes,swap them around and problem solved.If no then you have either a bad wire or a bad connection at the switch,which is tons of fun on a 70 model.The switch is A) almost impossible to repair if the problem is in the switch itself and B)unavailable from anywhere other than pulling it out of your other 70 model Mustang.That should be enough to get you started.Hope that helps.