Short list of electrical questions.

[nexizen]

I have a 71 F100 Sport Custom. Several electrical items don't work. I'm looking for some ideas of when might be wrong and how I might fix them.

1. Horn. This is kind of wierd. There wasn't a horn. Period. I'm not sure how this thing passed an inspection. So, I bought a horn and found the lead that SHOULD be for the horn (Yellow, blue?). I traced it back and found that it is directly connected to the starter relay. There isn't a horn relay as far an I can tell. I will take some pictures this evening.

2. Reverse lights don't work. The brake lights and turn signals are fine, just not the reverse lights.

3. I don't think the neutral kill switch is working. It's an automatic and I fired it up in reverse the other day. Now, I'm not a crazy person. I just didn't notice that it hadn't made it all the way into Park. (It's a bit sticky getting it to park.) So, yeah, the truck jumped 3 or 4 feet backward before I could get it to neutral. (It still started!) But this lead me to believe that my neutral kill switch (there is one on this truck, right?) isn't working.

4. Turn signal won't turn itself off. The truck has an after market steering wheel, so I'm assuming something isn't put together correctly. I will likely post about this in the steering zone of the forum, but since it's electrical and it's in the steering column along with the above items, I'm also listing it here.

5. Temp gauge doesn't work. It's pegged to the left (cold) and never moves. I tested the resistance of the sending unit and it seems good. I bought a new one anyway, but the gauge is still not moving.

Yeah. I think that will do it for this list.

Thoughts? Do you guys need some pics to better illustrate what I'm talking about?

Thanks!!!



Andrew

[fordman]

for number 1 i would liek to see a pic to make sure abotu the horn relay.

2 and 3 are the same problem. it has to do with a bad or bypassed missing nss on the bottom of the column.

4 could be the cancel cam or the cancel cam actuator on the aftermarket steering wheel.

5 if the sensor is good it must lie in the gauge or the wirign i would think.

[nexizen]

Where is the NSS?

I'll stag a video of the turn signal components moving and post it this weekend.



Andrew

[cdeal28078]

A lot of horn problems on these trucks are due to the ground link underneath or behind the rag joint is broke. Horn works by applying a ground to the circuit and if the ground strap between the steering column and steering gear is open the horn will not work. The horn relay is right near the start solenoid and is about 1" square if I remember right.
clint

[fordman]

the nss is inside the truck on top of the column under the dash near the firewall.

[1970FordTK]

NSS(netural safety switch) keeps the truck from starting in gear and it controls the back up lights on a automatic trans in our trucks. Its in the location fordman is telling you it is, dont fret I didn't understand the short hand for some parts for a long time.

[nexizen]

Alright. Here is a quick video of the wiring under the hood. This is my best guess of the horn's wiring. I also have some high res photos of everything if that would help. I basically traced the yellow/blue wire. Is this the right one? Isn't the horn relay supposed to be in there somewhere?

http://www.youtube.com/watch?v=XKQYKjf1Y70[/video]

I will look into the NSS tomorrow. I need to take my dash apart so that I can look into the temp gauge anyway.



Andrew

[fordman]

the relay is suppose to be on the front side of the relay. i couldnt see it or the wiring you started at the relay and followed the alternator regulator wiring. up to the actual horn wire. the horn relay plug is a triangle looking plug with three wires in it.

[mrollings53]

To fix your reverse light problem loosen the two mounting screws on your neutral safety switch and move the switch to where the motor starts and the reverse lights are on when they're supposed to. I had the same problem on my '69 F-250. Just make sure the ignition is in the off position when you loosen the screws or you'll short the fuse (yes, I did it). For the turn signal's not shutting off, its probably your cancel cam. Mine is bad too, I just manually move the lever. You should be able to find one at your local auto parts store, if not LMC Truck and National Parts Depot both stock the switch or the cancel cam itself. For your temp gauge it may be that the temp probe isnt screwed into the intake manifold. Whoever owned my truck before me installed an aftermarket gauge but didnt install the temp probe so it just hangs over the motor.

[nexizen]

So I took my gauge cluster out and I found some odd wiring.




What is this? Should it be there? If you look closely you will see that the black/red is cut and wrapped (the ends are not connected). The red/blue is a loop. If I remove this connector, the truck will not start. I'm still digging through the wiring diagrams, but I haven't figured out what is supposed to be here just yet. Thoughts?


Andrew

[fordman]

that is what used to be hooked to your nss. the wires that are capped off are your reverse light wires. the ones joined together is the nss part of the switch. if they are not hooked to the switch they will be put together liek that so the engine will start. its not the correct way to do it.

[nexizen]

Yay for bad wiring!

SWill Oreilly's/Napa have a NSS? Or should I be digging at the salvage lot?



Andrew

[FordJW]

MAC´s sells the Neutral Safety Switches, part# C7TZ-7A247-A

[nexizen]

1. Where is the NSS supposed to be located? How does it actually connect to the gear selector?

2. I pulled the gauge cluster apart and tested the temp gauge. If I supply it with 12 volts, it moves as I would expect. When I test the voltage that it is receiving from the backplane, I get a really wild reading. It bounces constantly. I followed the traces and found this gizmo:



What is it?

Wider shot:



On one side it shows ~12v. On the other it varies constantly (the same as I saw at the temp gauge). Is this normal? The other gauges all work fine; including the ones that also connect to this device.

Thanks again!



Andrew

[fordman]

ok if you get a bouncing readitn the ipvr which you have pictured is working good. it means you sender uni or wiring to the sender is bad.
the nss is on top of the lower column inside of the cab. it has two 5/16 headed screws that hold it onto the column. a tnag that snaps into the shift tube actuates the nss when you shift gears.