First of all sorry if this is the wrong section for this ?, don't know where else to put it.

I installed a 94 lt1 in my truck. It is a stand-alone system. I cut out all the preexisting wires going to my original motor. All I did was connect the correct wires to, 12-volts, 12-volt key power, and grounds as instructed. After the install of the lt1 in my truck, I noticed my speedometer wasn't working, and my fuel gage wasn't working. I was also having trouble getting my fuel pump relay to work. After lots of curse words and headaches I found the ground wire going to my fuel pump relay was reading hot instead of ground. Since it goes into the truck I just snipped it and ran it to a ground screw close by and it works flawlessly. (12 volts was coming to the relay through the ground, not from the relay.

The other day I found that the ground in my aldl, was reading hot.

Today I was checking out my fuel level sender and it works fine with the ohm meter. I decided maybe it wasn't getting power to it so I started checking wires in the plug in that goes to the sender and pump. I assume one wire should get 12 volts coming to the sender, then the other wire coming out should go to the guage. Both wires coming to the sender are measuring hot.

I remembered my speedometer wasn't working either so I unplugged it from the transfer case and took a reading on the two terminals, and once again, both wires reading hot!

These wires only read hot when the igition key is on. I don't undertand how this could be happening because I'm not blowing fuses and everything else works fine.

This is probably hopeless unless someone else has ran into the same problem.

Any takers?.....

 

By the way the engine isn't partially installed. The engine runs and drives great except for a small miss that i'm workin on also. All other electronics work fine. Headlights, cd player, heater controls. Just the fuel guage, and the speedo. This might be a good one for shoebox or dangalla if they come around. If you guys can't figure anything out give a reply so I know you've read it since it seems you guys are the ones to talk to. Thanks

 

I would say to trace the suspect wiring back to it's source.

 

This may be an odd question. Is there any way to tell which way the current is traveling other than cutting the wire and seeing which side is hot? I used to work at an auto store and the alternator/starter tester had some kind of loop that went around one of the wires for something but never understood what it was for. Was thinking that if I could identify which was the current was flowing in some of the wires, I may find which wire is bringing 12 volts to these ground wires......

 

As to which way the current is actually flowing, that can be a confusing answer, since the electrons actually move from - to + in a circuit, but most people consider that current flows from + to -.

If you measure voltage from either side of the load (pump, sensor, bulb, etc,) to ground, the side with the higher voltage is the side connected to +. I think that's what you wnat to know.

 

you need to get yourself a wiring diagram and figure out what you did wrong. alot of grounds are spliced into a single ground and my guess is that you have that spliced ground wired into a hot source.

 

If you had power wired directly into your ground circuit someplace, something would melt. If you have an ungrounded ground wire or poor ground connection, that ground can read +12V. I think you might be missing a ground. Try using the meter on 10A, and briefly measuring one of your 'hot' grounds, to chassis ground. If the meter is not pegged, it should be safe to ground that wire directly. Try adding a good ground to that circuit and see if the wire than reads ground like it should. Be very careful, and make sure the wire isn't getting hot, as grounding a real 'hot' wire = smoke. But grounding a badly grounded circuit is ok. If you get a big spark when it touches, don't attach it!!

 

For all the guys that have read the thread and are wondering what the he** is going on I fixed it this morning. I'm guess that I had a bad ground somewhere. I figured I would take one of my "ground" wires and really ground it and see if it sparked, got hot, or blew any fuses. It sent out a very very very small spark and wouldn't even spark at all sometimes. I held it to ground and nothing happened so I went ahead and grounded the wire and like magic everything works now. Speedometer, furl gage, everything. I guess somehow it was reading 12 volts from a bad ground or reading off another wire somehow. But thanks for all the help.