Reverse/Neutral safety switch

[wage92]

Im in the middle of wiring my 78 K5, and i dont remember how the reverse lights and neutral safety switch is wired? There are like maybe 4 terminals on it at the base of the steering column, i am assuming 2 of them are for reverse lights and the other 2 are for neutral safety? Does anyone know how this gets wiring or have a diagram of it? if i remember correctly, on the left there are 2 or 3 terminals vertically and then on the bottom there are a couple horizontally...any help would be appreciated.

 

[diesel4me]

Pretty sure your right,two wires go to the back up lights,the thick purple wires are the ones for the neutral safety mthat are interupted from the ignition switch to the starter solenoid..

I dont have my wiring diagram book handy ,otherwise I'd tell you what color wires are on the back up switch if I did!..but the plugs will only fit the right terminals I'm pretty sure..easy enough to see which ones are for reverse lights by shifting into reverse and checking with an ohm meter for continuity..

 

[wage92]

okay, only problem is, im rewiring the whole truck, so i do still have the original connectors but no wire that they go to lol

 

[diesel4me]

I usually take a trip to the local pick and pull when I need to figure things out like wiring...bring a phone with a camera!...sounds like you need a wiring harness anyway?...if I can dig out my manual that has a wiring diagram I'd be glad to help you figure out what color wires went where,right now its MIA in my garage...you might be able to veiw one on Autozone's website too..

 

[wage92]

i have an aftermarket harness thats doing pretty good so far, i have my old one too so im trying to sort through that, reverse lights are easy as far as i can tell they would just be power in and ground out (and i want that hot at all times correct?) and i found this for the neutral safety switch, does it look right? http://brochures.slosh.com/wiring/78 Chassis 1.pdf

 

[wage92]

figured it out and got it wired. I interupted the purple ignition switch going from the column to the starter and put the connector for the neutral safety switch in line with that. so it will only work in park/neutral.

For the reverse lights, i hooked up the lights to one of the leads and an unused hot at all times wire on the other lead, so those will be powered when its dropped into reverse. And i checked for continuity to make sure. Good to go

 

[diesel4me]

My obsolete POS computer just goes into seizure mode when I try opening PDF files,so I cant help you much I'm afraid...

I do think the back up lamps get power from the brake and tail lamp fuse,so it is possible they are hot even with the key off...I think they ground back at the sockets though,the back up switch just connects the power wires together at the switch to make them come on I think...when I put my back up lights to a manual toggle switch I just unplugged the wires at the N/S and jumped the plug with 2 wires to the toggle.so I can leave them on while plowing,loading the truck up at night,or blind a tailgater!..