tach off when lights come on

[brokebyford]

Merry Christmas everyone.I recently had a problem where my tach stops working whenever the headlights come on.I think it might be a ground problem of some sort but im not sure.Has anyone had this happen to them and if so was it an easy fix?

[David]

definately a ground problem, same problem here, but i think it can effect your gas
gauge as well.

[Blue Oval]

I fixed mine by making a jumper wire between the lights on the instrument pod. It can also be fixed by grounding an orange wire down by the kick panel. I suggest you go to the Hot Rod Lincoln forum over at FordvsChevy.com and repost your question for clarification. I did not do the orange wire fix, but I imagine that it would be easier.

[brokebyford]

yeah my gas gauge is shooting up to full also as soon as the lights come on.I tried that orange wire fix but for some strange reason when i put the jumper on that orange wire my right side directionals stopped working.

[RODDMOD]

You have the wrong orange wire.

[brokebyford]

Rod How many orange wires are in there?I only saw one but i'll give it another shot thanks.I bought my Mark because i was having the same sought of problems with my digital dash in my 92 conti.Lincoln told me the dash was bad so I bought a new one for the 92.Cost me over 400 beans and still had the same prob so I I parked the conti in my driveway and bought the Mark to get a break from the aggravation.Now the Mark is driving me nuts too.Guess i'll need a bigger driveway.LOL Thanx for the info Ill try again

[RODDMOD]

Hi brokebyford A couple other guys that went into the wires by the drivers kick panel had said that there are two org wires, I myself went and pulled the speedo cluster out and ran a ground to the org wire in back of the I.P. The famous org ground wire goes to the anti slosh board (also called the message center interface module) mounted to the back with one screw and has fingers that connect to the I.P. This org wire goes to this board and is the ground for the sender in the tank.

[brokebyford]

Thanks Rodd I'll pull the instrument panel tomorrow and look back there for the orange wire.It's really not a big problem but the car looks and runs great and something small like that has a way of really getting under my skin.Thanx again,Eddie

[brokebyford]

Rodd,Thanx for the great info.I pulled the speedo last night about 4 am.I tapped off the orange wire at the back and now all the problems are gone(tach,lights,Message center alarm).It made me so happy I forgot about all the money I left behind last week in Vegas.Now if i can fix the problem with the electronic dash on my conti life will truly be excellent.It has to be the same sort of grounding problem as with my Mark.I'll have to pull out the electronic cluster and see if there is an orange wire back there.Wish me luck!!! :D

[TW/92LSC/SE]

Thanks for replying. Its always good to hear if a suggested repair works.

[Bluegrass]

...I've looked up the orange lead at the cluster, lead 89 orange. It goes to one side of the fuel sender and also connects to a speed control sence pin on the engine computer.
...The ground for the cluster is a black lead 57.
...I would have a problem with grounding an orange lead that isn't a ground lead. You have managed to apprently supply a fix but may now have other functions not working correctly.
...Not trying to be disagreable, but thought this might be some info to keep in mind.

[Foxman]

I am just about to attempt a repair in this area. Am I to understand that the orange wire fix in the kick panel is not the optimum solution to this problem? If not, can you really fix this situation without cluster removal? I want to do it right, once!

[Bluegrass]

In my opinion, not, for the reason mentioned above. There may be a bad ground, a plugup or something thats causing the problem. Grounding a lead that doesnot normally have ground on it is questionable. I don't have the correct fix for the problem only to make light of the orange lead situation.
Applying ground on a lead other than black is what attracted me to post an answer.
If there is someone else who has the drawings to verify my findings, please come forth.
Try applying an extra ground to the black lead and see if it clears the problem.
If your satisfied with grounding the orange lead to clear the problem, then so be it.

[TW/92LSC/SE]

When you look at the EVTS Manual under Instrument Cluster (analog) the Org89 wire is the return ground for the fuel/tripminder. It returns from the inst.panel to connector C208 then connects internally in the fuel tank to the sender then it finally grounds to the tank. With the Digital dash the Vehicle Speed Sensor also uses the Org89 wire to ground. I can see no problem with doing RoddMods fix. However I would take C208 apart first to check for continuity to the tank then check the other side of the connector for continuity to the dash. Perhaps its not the 89 wire causing the problem. It could actually be the Black57 ground wire that has corroded or come loose behind LH side of I/P, RH side of steering column support. The C208 is one of four side by side connectors located forward of the fuse box towards the firewall. Its a 12 terminal connector.

[RODDMOD]

Yes the problem is at the grounding block up buy the steering column, but it is tough area to get at, that is why the fix is easier at the org wire on top. The org wire is suppose to be grounded, this is not a improper fix for this problem.

[Icarus]

If you look at the Electronic Control Assembly, the Orange wire does goto ground for the Fuel Sender...
At the dash it looks like it is connected to a Black/White wire thats going to ground as well...
I agree with Bluegrass and TW as well, try regrounding the wires that are definate grounds before trying with others to clear it up so it is still giving power/ground were it should be...
Jon