Neutral Saftey Switch --- Painless (painfull) Harness

[Gordonr1973]

HI,

I'm having a heck of a time getting this harness buttoned up...

Can anyone tell me where this loose purple wire should be connected to? In the way too brief Painful instructions, it just says to use it but it doesn't say where...

As you can see in the picture, I plugged in the purple wire from the ignition switch/connector to the neutral safety, but there should be another connector somewhere on this white plastic bit that should accept the loose purple wire??

Or did I place one of the other wires in the wrong spot??

Thanks!

[Mr Pops]

Is there anything that doesn't work?

[Gordonr1973]

Nothing works b/c I'm just putting in the harness now.

I'm trying to get as much wired in as possible before I wire in the LS swap harness inside the cab.

Then I'm going to wire what is outside of the truck, then put in fluids then turn the key in about a week if I have enough time off work.

I shoulds say too that I replaced the stock wiring with a Painless Harness 10203 (I think) and that the Swap harness is one from PSI...

[Mr Pops]

So your new harness looks nothing like the old one I take it? So even if I took a picture of mine, it may not help?

[Gordonr1973]

If you could take a pic of the cruise control wire connector into the regular in-cab harness that would be great...my pre-tear down pics don't show it.

[J Knight]

It looks like the cruise control wire to me.

[Gordonr1973]

I'm pretty sure it isn't --- the wire coming off of my cruise control lever has 4 small wires that are sautered onto a 4 - way blade plug....it should plug into a similar connector.

[J Knight]

I thought a painless wire harness had each wire labeled every few inches as to what they pluged in to?

[Gordonr1973]

I will NEVER buy a Painless product again...

Sure, they have tiny labels printed on the wires of where they go, but they are generic harnesses that do not have any of connectors on the wires, so you have to cut the wires to length, pull your 30 year old plastic connectors off your old harness to reuse...not to mention that more thanm a few wires may not be for your application so the instructions say "just tuck them up and out of sight"....when you have several wires that are marked for the A/C power source which one exactly is a guy supposed to use??

It's really well-marketed, too bad they cannot put more value into it.

[Mr Pops]

My truck doesn't have cruise control, sorry.

[Maxzillian]

I'm assuming this is the lead the PCM uses to determine if the truck is in park or neutral to help with the idle control logic.

I ran into a very similar dilemma in wiring a LT1 harness (not Painless, a modified Camaro harness) into my 1985 C-10. In my case I plugged the park/neutral lead into the bottom left connector of the park/neutral/reverse switch at the base of the column. One lead led to the LT1 harness and the other went to chassis ground.

I did some probing around and the far right plug that you are currently using is shared with one of the terminals on the bottom right, but I also recall that it either worked in only park or only neutral. I've slept a few nights since then!

Ultimately your best bet is to determine where those two green wires go. If one leads directly to chassis ground, the purple wire should be attached to the other.

[Gordonr1973]

Those two green wires were marked by Painless to be the reverse lights...but I will double check them in the morning...maybe one of them is the now famous "wrap it up and stow it" extra Painless wires that were thrown into the harness and my extra purple wire goes in its place...

Just fyi: my painless harness did not come with any wiring for the power windows or locks save the hot wire going to those switches!

I would have been better off just fixing a few hacks in my OEM wiring harness and saving $600!

[Maxzillian]

If that's the case, you've got some pin swapping to do. The reverse lights should be wired into the middle plug (what is currently pink and black). But you may also want to verify that with a multimeter, just in case.

The plug your green wires are going into should have continuity when the shift is in park or neutral. Where your pink and black wires currently lead into should have continuity when you are in reverse.

Now, that said, depending on your year of truck, you may have a mechanical safety for the starter. Such as with my 85, the key will not turn to the start position unless you are in neutral or park, rendering any sort of electrical safety redundant.

I've been reading through the manual (and manual 10205 as it deals specifically with the chevy, http://www.painlesswiring.com/Manuals/10205.pdf )and frankly I'm shocked they can't be bothered to include a schematic with their harness. However, reading through the wire connector index I think I know what you need to do:

The purple wire appears to be #919. Based of the manual and what I know, they intended for you to plug both of your purple wires into the location where you currently have your green (reverse) leads plugged into. This would give you a starter neutral/park safety. However, if your truck is like mine and has a mechanical lockout for the start position, you can just splice the two purple wires together and reduce the complexity of your system. (after all, who needs another switch that can fail when the truck already has a sturdy and reliable starter inhibitor?)

Your two green wires should be in the plug where you currently have your pink and black wires.

I'm not sure what to do with your pink and black wires. The pink wire appears to be a supply for the cruise control system, but I'd need to know the number of the black wire to make any further guesses. Looking over schematics for my 85, there was a pnk-blk wire on the factory harness that went from the fuse block to the "Cruise control activator" and also supplied power for the speed sensor on the back of the instrument cluster. Either way, I don't believe it should be plugged into the park/neutral/reverse switch.

[Gordonr1973]

Thanks for that info!

I did swap the purple wires #919 around on the switch as you said, that makes alot more sense that the white plastic switch does complete the curcuit from the key to the starter when tit is in neutral or park....and my column is new enough to have those safety switches as well that the key will only turn when the gear is in park or neutral.

I also moved the green wires over to the other connector.

The only thing left on the column is the cruise control....the black wire I added in myself as a ground when I thought it went on that switch so I will remove it. I will look for the stock pink and black wire on the old harness next.

Is the cruise control activator a black or green plastic box that is along the length of the stock harness?

My Haynes manual has very basic schematics.

[GmtGmt]

the cruise control brain is the black box by the pedals, the small green box that has a 3 or 4 wires running from the speedo is converting the signal from the speedo so the brain can use it.

KM/H speedos a green box and MP/H has a Yellow box

[Gordonr1973]

Thanks for the replies! I might actually be starting to see some daylight now thanks to all your guys help!!

Ok, I got my old harness stripped so I can follow the wires.

Here in the first pic is what I surmise is my cruise control system.

The black box is the cruise control brain.

In the second pic, what do these plugs go into??

The pink wire with the black stripe is my power wire that plugs into the fuse box I think....and this is the existing wire I have near my column in the truck right now that was supplied in my Painless harness.

In the 3rd pic, with a LS swap, would I keep the vacuum line for the brake?? I think it is a cancellor line that would interput being in cruise mode if I hit the brake.

I think these pink and purple wires are engage my brake lights if I hit the brake pedal??

[Maxzillian]

According to my schematics, the 4 pin plug is what goes to the "Cruise Control Activator." I assume this is the turn signal stalk as I see no indication of it anywhere else on the schematic.

The single black plug goes to one of the bus-bar grounds in the cab.

The brake switch does release all vacuum stored in the cruise control unit to release it as quickly as possible and serve as a secondary fail safe, I assume.

Fortunately I'm still young and limber enough to hang upside down in my truck so I could take a peek underneath the dash and make heads or tails of how it works:

The black plug with the two greys and one grey/black wire plugs into the back of your main/existing brake switch. This plug is the brake switch cancel for the cruise control.

The two wires, while a different color in your case is for the lock up torque converter and provided 12 volts to the torque converter when the brakes were not in use. Why they put it on the cruise control switch is beyond me!

I confirmed that the 4 pin plug is for the cruise control switches on the turn signal stock. On my truck the plugs hangs on a bracket on the steering column.

Now, based off my own experience with my LT1 swap, I have some advice for you:

1. Since your ignition switch has a mechanical lockout for the park/neutral start, I advise you splice the two purple wires together.

1a. Use the open terminals on the park/neutral switch for the LS1 engine harness. If you're using an automatic transmission, you may need this to indicate to the PCM when the truck is in neutral or park. For the LT1 I had to ground one pin and connect the other to the PCM.

2. Use the cruise control vacuum switch for your brake indication for the LS1 PCM. At least for the LT1, this proved to provide the correct logic in that the switch provided 12+ when the brakes were not active.

Edit: Thought you may find this handy:

[Greenlee]

I'm wiring my truck right now also. I'm not sure how helpful this is because I'm using a stock harness from an 89' Suburban, but the cruise control harness plugs into the stock fuse block where it say "ign". Once I unplugged it here it separated from the rest of the harness. Similarly, the power window and door lock harness plug into the fuse block one time, and the air conditioning harness plugs into a trunk in the stock harness with one gray plug.

I found it easier to separate those three harnesses from the main harness so that I was dealing with a manageable number of wires. Now that I got the engine to run, I will go back and deal with the cruise, power windows and A/C.
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[Gordonr1973]

Thanks for all the info!

I'm gone for a few days but I will definitely separate the harness when I get home and install them separately.

[Gordonr1973]

Just an update, I've deleted the purple neutral safety wire as mycolumn key has the park & neutral lock on it.

I've also corrected the reverse lights.

Now I'm trying to figure out my PSI harness conections in the cab...here's a pic of the instructions ... basically everything without a dot beside is stumping me!

Where would the TCC connect into?? Wouldn't that be a part of the cruise control system?

Thanks in advance!!

[Jonboy]

You need to change the brake on/off (BOO) switch out if you don't already have the one with two sets of two pins. The front set will go to the brake lights (normally off until brakes are applied), and the rear set will use your yellow and purple torque converter clutch (TCC) wires. They will be hot until the brakes are applied. The switch is powered by the brake lights.

The orange P/N wire will go to the terminal on the neutral safety switch (NSS) you started out with the purple wire on (the terminal that is all by itself). That will let the computer know if the truck is in gear or not.

For teh chassis ground, those would normally be attached to a bolt at teh rear of the heads. I would run your battery ground to the engine block, then a strap from the block to the chassis, and a strap from the block to the body. You can't have too many grounds, especially with a PCM. If there isn't a sufficient ground, you will be chasing your tail eliminating silly electrical gremlins.

The PCm connections are the large connectors that go to the PCM; same for the TAC (throttle actuator). The TAC is the box that wires to the accelerator pedal.

I went through a lot os this with my TBI swap. It's mostly the same idea.

[Gordonr1973]

Thanks Jonboy!!

I went out and bought the 4 pin brake switch today and installed the wires on it as well as the orange on the neutral safety switch as you said.

I still have a blue wire for the ground side of the fan --- I think that Entrophy had prohgrammed my electric fans to start at =certain temperatures on their own but maybe this wire gets connected to the Painless harness wire #901 in the headlight section for the cooling fan??

If someone has knowledge on that I'd appreciate it!

As well as "alternator exciter" wires??? How are those connected and is there a specific spot on the ignition switch that they would connect to??

[Jonboy]

Which alt. are you running? I did the CS144 swap on mine, and just put the brown wire to a switched power source on the fuse box, with a peanut bulb in line for resistance. I tried to use an aftermarket conversion harness, but couldn't get any of them (4) to work. It was easiest to just cut one up as necessary.

[Gordonr1973]

I'm doing a LS2 6.0 liter swap into the truck. So its the alt that came with that motor which has a PSI conversion harness for the swap that I'm trying to mate up with a Painless wiring replacement kit for my truck.

There's so many wires in the Painless kit that need don't to be used is what is confusing me with this!