Wiring backup light switch/sensor

[o2bgitarn]

1980 Fiat Spider EFI with no wires leading to the backup switch on rear of transmission. I have read the posts and have located wires with the white connectors and blue/white togehter and a white wire that transition into 2 black wires once they enter the gear shifter cover but they are attached to different sensor on the top of the transmission. Firstly I am wondering what that top sensor is for and secondly any ideas on how to proceed in getting wires to my backup sensor? I have not figured out how to post pics on here yet or if its possible? Cheers

[spider2081]

THe back up light switch for an 1980 Spider is an assembly complete with the 2 pin connector and wires. It mates to a 2 pin connector that has a blue/white wire and a white wire in it. The connector is located below the center consul wood cover the shift lever passes through. There are a couple press pins near the ash tray holding the wood panel in place. carefully pull up on the panel en the area of the shift boot. Sometime the pins are hard to disengage. The connector is usually forward ot the shift lever.

If there is a second switch on your transmission it should be on the passenger side above the transmissions fill plug. I don't think its used on your car. Its for cars that have a carburetor

[o2bgitarn]

Hi thanks for the reply. I located that wire and connector combination and traced it through the transmission opening but it appears to connect to the the top of the transmission (switch/sensor)? I do not see any other wires leading down to the sensor on the back of transmission. Do you think maybe the PO attached these wires to the wrong switch and if so what is the switch at the top of the transmission for? Its hard to get at so i don't want to pull it off if unnecessary. Is there a way that I can to send pictures to you? Cheers

[spider2081]

I assumed your car is a 5 speed manual shift transmission. Is manual or is your car an automatic transmission??
I don't have much experience with automatic transmissions but believe the neutral safety and back-up light switches are on the top of the transmission forward of the shift lever.

[o2bgitarn]

Its a 5 speed gearbox so just not sure what the top one is and why those particular wires seem to be running to it....I will just have to keep searching and see if I can find any cut wires etc.

[o2bgitarn]

Its a 5 speed gearbox so just not sure what the top one is and why those particular wires seem to be running to it....I will just have to keep searching and see if I can find any cut wires etc.

[o2bgitarn]

Mystery has been solved! Thanks to you spider 2081 you got me thinking about that top sensor/switch and it didnt make sense to me that the wires matched up to the backup wiring diagram so I unplugged the wiring from the loom and jumped the wires....VIOLA we have backup lights sooooo.........the PO must have plugged the backup wires into a spare plug that is for that top switch/sensor. Either way I have backup lights so appreciate the help and will order the pigtail wire connector for the backup switch since it is AWOL. Now if I can just get power to my fuel pump so I dont have to hot wire it from the fuse panel I am in business. I started with swapping out the dual relay and checked the AFM and getting clicks form the relay with ingition turned all the way on but pump not running. The pump runs and the car starts and runs if I put direct power to the pump from fuse panel so I figure the pump is functiong properly. Any input is greatly appreciated.

[Nanonevol]

Is what you're looking for the wires coming from the back up light? Sounds like you need a wiring diagram for your year car which would show you the wire color. Or you could try following it from the light to the fuse and then to the shift lever area.

[o2bgitarn]

Thanks problem has been solved the PO had the wrong wires plugged into the wrong plug in transmission tunnel. Cheers

[spider2081]

When you jump power direct to the pump you are bypassing the FI inline fuse usually located behind the fuse panel tucked in the wire harness near the hood release handle. Have you checked that fuse? it is common for that fuse to get corroded and make poor connection in its holder.
I think its safe to assume the fuel pumps ground connection is ok as the pump runs when you jump power to it.

[o2bgitarn]

Yes I have checked the inline fuse and put a new one in....now about the ground the starter iteslf is ground to the frame underneath the car so with the hot wire it should always start (at least I know the pump is working) I am going to check the harness ground at the left tailight as I have been reading several posts about this being an issue. Several posts suggest that this is a hard place to get a good ground and a common issue so must be checked off the list.

[spider2081]

Many relocate the ground in the trunk using a machine screw nut and star washer. You might consider that.
"Hot all the time" power passes through the in-line fuse to the dual relay terminal 88y on a brown/white wire. If the fuel pump relay is properly activated power leaves the relay on contacts 88c to the Aux Air Regulator and 88d to the fuel pump. So I like to check and see if the Aux Air Regulator has power when the ignition switch is in the "start or run" positions and the Air Flow Meters flap ois partially open.

[o2bgitarn]

Excellent thanks I will try that.

[o2bgitarn]

Well you will never guess what I found......the inline fuse for the brown/white wire was the culprit. It was one of the first things I checked before and the fuse looked fine. I took my test light and started snooping around and found that power was indeed coming into one end of the fuse but nothing on the other side so it had to be the fuse. I pulled it again and looked closer......the metal strip along the side was intact and not burned through BUT when I checked the ends I found that one of the end caps was missing so the current could not travel through the fuse. Crazy eh.....all that hot wiring etc the PO did and messing around all for a 10 cent fuse. Thanks for all the help! Cheers

[spider2081]

Great enjoy your ride