Blackdog36

iTrader: (3)

Having trouble with my tach needle working. I've swapped in an LS3 engine and ECU from a 2012 camaro into my 92 camaro. Had it tuned and vats turned off so engine works. I've replaced tach gauge circuit board from CajunTach. Also installed pull up resistor mod. New gauge circuit confirms I am getting power and signal to tach as both led lights are on. I took my gauge cluster plastic cover off so I can physically touch the tach needle. I noticed that I can move tach needle with finger, there is no resistance along with needle dropping quickly to either side. Conversely, my speedo needle has some resistance and will stay where I locate it. On back of gauge cluster, looks like tach needle is connected to a metal pot which I am assuming has copper coil inside to rotate needle. Is this pot of my tach gauge broken?

QwkTrip

iTrader: (22)

My tach wouldn't even flinch after my LS swap and it turned out to be a screw missing in the gage pod that grounds the tach to the green screen. I mean it had to be me that left it out but I don't remember.

Blackdog36

iTrader: (3)

Thanks QwkTrip. You always have some good advice on my LS swap questions. I will call the CajunTach guy and see what he says. Maybe related but my speedo needle does not work either. I connected speedo wire from new ECU to proper pin on gauge connector. My gauge cluster battery and coolant temp gauges do work. I took gauge cluster out to change light bulbs over to LED. Worth checking to see if any ground screw is loose. So close to getting on road this season.

Blackdog36

iTrader: (3)

Quick update. Spoke with CajunTach owner who noted that speedo and tach needles do feel very loose with no resistance to fingers. So my needles are probably fine. I replaced TR6060 speed sensor but that did not make gauges work. I will have to keep troubleshooting. I think big clue is that my speedometer, tachometer, oil pressure, and fuel gauges do not work. However my coolant temperature and battery voltage gauges work. Car does run with gauges not all working.

scooter

iTrader: (11)

I think I remember reading that the output of the later ECUs (not the red/blue/green style) won't drive the factory tach properly. You might need to buy a tach adapter.

Oil pressure could be that you just didn't do something correctly, but since the fuel gauge doesn't work I would be inclined to say that there is another problem. There should be no connection to an engine swap to make the fuel gauge not work unless you messed with the tank/sender

Blackdog36

iTrader: (3)

Thanks Scooter. Tried something else today but no luck. This is getting frustrating. Plus my power steering pump is making wild noises Summary below. I will trouble shoot more tomorrow, especially with testing connectors for resistance per shop manual. Just too many dash items not working which seems odd. I know most swappers had to do resistor mod to tach input wire which I have done. I don't think adapter is needed in most cases.

1) Bought aftermarket tachometer gauge and hard wired it to black dash connector. Needle did not move at all.
2) Working LED lights on new tach circuit board from CajunTach confirms I am getting power and signal to tach on the black wiring connector at dash.
3) Instrument cluster lights for headlights & turn signals work so getting power to cluster. Brake lights work too.
4) I read that most LS swappers had to install oil sensor near oil filter and connect to gauge. The LS3 oil sensor I believe just tells ECU engine has pressure so it can allow engine to turn over. I was expecting oil sensor not to work.
5) I only have few gallons of gas in tank. Needle is all way to E. Maybe I messed something up when installing walbro 255 pump in the tank. Fuel pump and injectors do work at proper pressure.
6) My wiring harness was built by company specializing it this type of work and is very well made. Everything connected up properly and engine does fire up. I have driven it around my subdivision few times.

Blackdog36

iTrader: (3)

Some good updates after this weekend.

Per shop manual, I tested again tach and speed wires at dash connectors. You are supposed to get 12 volts with multi meter across signal wires to ground. I was only able to get 12 volts when I used ground screw under dash. I could not get voltage when touching appropriate ground wire on connectors. This seemed odd to me why I would not be getting ground ability from these two connector points. So I took some spare wire, jammed one end into both connector ground slot and other end tied to ground screw I knew was good. Testing again with multi meter worked now! Somehow these connector ground wires are not properly tied to ground. To test cluster, I put gauge cluster back on and started car up. My oil and fuel level gauges now work! Although tach and speedo needles did not work and were pointed to left position (zero), they no longer moved effortlessly like before but have resistance to my finger. I think this means the needle pots are working properly.

Took car for trip around block and both needles do not work. I thought maybe speed would work but not tach as setting in ECU may not be at proper setting. More troubleshooting required.