[Rob B]

I need some help to identify and also to make sure my guesses are correct on some connectors from the dash wiring harness on my 70 GTO, 4 speed, non RA car.

Picture 1: I am assuming is the connector to the start switch on the clutch pedal? (4 spd car) I found the other piece to this wire cut free and twisted together and assume it was bypassed previously.

Picture 2: No idea what this if for. Assuming it is for power locks or windows which this car does not have?

Picture 3: Short brown wire that comes of the main harness by the light switch. I am assuming this is to be used if the car had the delayed headlight option?

Picture 4: This was the extra orange accesory wire that I plugged the connect from the hood tach into. Is this correct? I don't see anywhere else to plug it into and my assembly manual shows it going thru the firewall and connecting under the dash like this.

Picture 5: This piece is basically between the radio and the steering column. Where does it go??



Any explanations would be greatly appreciated so I can wrap up the underdash of my car.

[Rob B]

Picture 6: This is a single black wire that comes out of the new Wiring harness around the area of the brake booster.

Picture 7: I assume this brown wire runs down to the proportioning block along the frame by the Z bar assembly. The end is missing and the wire is a little short.

Picture 8: I found this vacumn tank with all the parts that came with this car. I'm not sure it even goes to it. If it does, where does it mount and what is it for? It only has 1 line going into it. Baffled on this item. Car does have Factory AC.
Picture 9: This connector goes along the side of the radio and steering column. I am assuming this is for the connector for the convertible top switch if my car had a convertible top.

Again any help on these would be greatly appreciated.

[Evil Stu]

Rob,

#8 is the delayed vacuum break, part of the choke system. Line goes to the vacuum pull off at the carb which should have a 2 nipple pull off. These are often disconnected and a one nipple is used. Tank itself mounts to the front of the P/S inner fender.

HTH

Stu

Is it a factory harness(colours?)

[robz]

Rob, not sure if '70 changed the colors of some of the connectors, as mine are '69.
Pic 1, does look like part of the clutch safety switch (I have posted a pic of an old switch with part of its connector still attached). Pic 5 is a fiber optic cylinder that attaches to lighter housing (see my pic below). Pic 9 looks like the under dash courtesy lamp connector (see my pic below). Pic 7 looks like the low brake fluid switch wire. I'll add on later as I look at the rest of your wiring pics.

[Evil Stu]

#1 clutch/neutral safety switch
#2 auto trans kick down switch (I think, never had a stick car. Don't know for certain it is there on a MT harness)
#3 light minder. headlight delay is lt. blue. There's also an accessory feed comes off the same source as the brown to the heater control. hard to tell from pic.
#5 Ashtray light.
#7 Tan wire to the low brake fluid switch at the brake block.

[carguy66cars]

OK Rob, Going to try and answer some of these! I would say #9 is for automatic trans. kick down. #7 is for the brake porportioning valve. #6 is probably for the horn relay. #5 is lite for the ashtray looks like. You are correct on #1. #2 is back up lites or something on the steering coloumn. #4 is for power seat or other power options, not sure if its correct for tach power!

Lyn.

[Rob B]

Originally Posted by Evil Stu

Rob,

#8 is the delayed vacuum break, part of the choke system. Line goes to the vacuum pull off at the carb which should have a 2 nipple pull off. These are often disconnected and a one nipple is used. Tank itself mounts to the front of the P/S inner fender.

HTH

Stu

Is it a factory harness(colours?)

After flipping thru my assembly manual, I found the page on this piece. Just seems wierd that it only has one vacuumn line going to it. My pull off has two lines on it like the manual shows so now I know where that goes!

[Rob B]

Originally Posted by robz

Rob, not sure if '70 changed the colors of some of the connectors, as mine are '69.
Pic 1, does look like part of the clutch safety switch (I have posted a pic of an old switch with part of its connector still attached). Pic 5 is a fiber optic cylinder that attaches to lighter housing (see my pic below). Pic 9 looks like the under dash courtesy lamp connector (see my pic below). Pic 7 looks like the low brake fluid switch wire. I'll add on later as I look at the rest of your wiring pics.

I think we're correct on Pict 1. Like I said before, looks like it was cut and bypassed by original owner. Would have been simple to do.

Your picture 5 explanation makes since based upon its location. I'll look tonight when I get home to see if it can clip on the side of the lighter.

Pict 9 is an interesting explanation. From what I can tell, I don't have a harness for under dash courtesy lamps nor one for the glove box but it has a switch in it. Wonder if I'm missing that harness all together? Did all GTO have the courtesy lights??

Picture 7 is correct. I'm just missing the end and part of the wire going to have to figure out how I'm going to fix that one. Might see if I can get a donor and splice it in back in the harness so you cant see it.

Thanks for the help!!!

[Rob B]

Originally Posted by Evil Stu

#1 clutch/neutral safety switch
#2 auto trans kick down switch (I think, never had a stick car. Don't know for certain it is there on a MT harness)
#3 light minder. headlight delay is lt. blue. There's also an accessory feed comes off the same source as the brown to the heater control. hard to tell from pic.

#1 Neutral safety is separate so it must be clutch switch.
#2 thought about too. I am assuming they use the same dash wiring harness for both MT and Autos.

#3 is an extremely short brown wire, one connector. Thinking it has to be some kind of accessory wire but not sure since its brown. There is nothing underneath close that it could connect to.
Thanks also!!

[Evil Stu]

Originally Posted by Rob B

#3 is an extremely short brown wire, one connector. Thinking it has to be some kind of accessory wire but not sure since its brown. There is nothing underneath close that it could connect to.
Thanks also!!

It's the accessory feed then. Page 12-65 of your manual, right edge of the first panel of the fold out, right above the bold line, right in the crack.

Stu

[Rob B]

Originally Posted by carguy66cars

O#4 is for power seat or other power options, not sure if its correct for tach power!

Lyn.

Based upon the assembly manual, The power wire for the hood tach routes thru the firewall and connects to a power accessory style connector. My old harness still had the old grommet and all the wires are identical so I know it came inside. Based on it's length and the style connector it has on it, the orange accessory wire is the only place it can go. Looks like also you can stack multiple accesories on this style of connector.

Thank you also!!

[Rob B]

I have 2 diferrent explanations for #9 and what I think it is possibly for. (the orange and white wire between the radio and steering column) Based on it's length, it has to plug into either a switch on the dash bezel or another harness (that I don't have) right where it's at.

[rolling money pits]

# 1 clutch safety

# 2 see below

# 3 light minder option connector

# 4 see below

# 5 cigar lighter light - clips to the outside of the metal case. NOT fiber optic, it takes an 18XX series mini bulb. if you dont have a bulb in there the contact will short out the dash lights and youll blow the little 5 amp fuse randomly, ask me how i know this it pulls apart where the wire goes into the canister, just grip the outer edge and pull apart.

# 6 should go to horn relay or wiper/washer motor?

# 7 brake fluid warning connector wire, should have a female bullet connector on the end to plug into the prop valve switch

# 8 no idea, sorry

# 9 see below

#s 2, 4, 9 - it LOOKS like you might have a harness for a ragtop # 2 might be the top switch, # 4 is power to the top pump, and # 9 is the connector for the under dash lights and rear arm rest lights. since rag tops didnt have dome light, they spun off that curciut to the other 4 lights.

The other thing you may have is a harness for a 69 auto trans car. # 2 is the correct connector for one for the auto trans kickdown switch, in shape and wire coloration. and could quite possibly be for a ragtop, or a hardtop with optional under dash lights. still wouldnt explain the heavy orange accessory wire though.

Edit - nevermind, orange/pink #2 is correct for 70 as well - auto trans. IIRC, the stick cars had a harness extension for the neutral/clutch safety switch. the auto cars the harness end plugged into the NSS up on the column, for a MT car the switch was by the pedal, so there was a small jumper harness going from the dash harness down to the switch. you say theres something twisted together under there, two purple wires?

[Evil Stu]

Originally Posted by Rob B

I have 2 diferrent explanations for #9 and what I think it is possibly for. (the orange and white wire between the radio and steering column) Based on it's length, it has to plug into either a switch on the dash bezel or another harness (that I don't have) right where it's at.

Orange and white is some kind of accessory lighting with a switch. Always there on a ragtop like RMP says.

[Rob B]

Originally Posted by rolling money pits

# 1 clutch safety

# 2 see below

# 3 light minder option connector

# 4 see below

# 5 cigar lighter light - clips to the outside of the metal case. NOT fiber optic, it takes an 18XX series mini bulb. if you dont have a bulb in there the contact will short out the dash lights and youll blow the little 5 amp fuse randomly, ask me how i know this it pulls apart where the wire goes into the canister, just grip the outer edge and pull apart.

# 6 should go to horn relay or wiper/washer motor?

# 7 brake fluid warning connector wire, should have a female bullet connector on the end to plug into the prop valve switch

# 8 no idea, sorry

# 9 see below

#s 2, 4, 9 - it LOOKS like you might have a harness for a ragtop # 2 might be the top switch, # 4 is power to the top pump, and # 9 is the connector for the under dash lights and rear arm rest lights. since rag tops didnt have dome light, they spun off that curciut to the other 4 lights.

The other thing you may have is a harness for a 69 auto trans car. # 2 is the correct connector for one for the auto trans kickdown switch, in shape and wire coloration. and could quite possibly be for a ragtop, or a hardtop with optional under dash lights. still wouldnt explain the heavy orange accessory wire though.

Edit - nevermind, orange/pink #2 is correct for 70 as well - auto trans. IIRC, the stick cars had a harness extension for the neutral/clutch safety switch. the auto cars the harness end plugged into the NSS up on the column, for a MT car the switch was by the pedal, so there was a small jumper harness going from the dash harness down to the switch. you say theres something twisted together under there, two purple wires?

great info on #5 for the cigarette lighter, I'll check the bulb when I get home also.

It appears there are numerous,possible uses for #9 all of which my car doesn't have. The best explanation is the connection for under dash lights which may have been there but I don't have now. It appears I have everything correct except for a coupe minor things I need to fix/ finish.
anymore explanations are still appreciated as everyones cars had different options.

It appears there is just one under dash harness used on a 70??

[Rob B]

Originally Posted by Evil Stu

Orange and white is some kind of accessory lighting with a switch. Always there on a ragtop like RMP says.

Quess I should check into the under dash courtesy lights and harness!

[rolling money pits]

Originally Posted by Rob B

great info on #5 for the cigarette lighter, I'll check the bulb when I get home also.

It appears there are numerous,possible uses for #9 all of which my car doesn't have. The best explanation is the connection for under dash lights which may have been there but I don't have now. It appears I have everything correct except for a coupe minor things I need to fix/ finish.
anymore explanations are still appreciated as everyones cars had different options.

It appears there is just one under dash harness used on a 70??

seems that way, only variation i'm seeing is with or without gauges according to PY and ames catalogs. the other options were simply add-on harnesses to what's in the factory one. now, that could be nothing more than a "short cut" on behalf of repro harness makers, or what the factory did to achieve the same economies. i was wrong on the power top switch though, just looked at them and the connector for the switch is a three wire. so # 2 is for sure the auto trans kickdown.

youre probably fine with what you have, it's normal, the only things you appear to need is to fix whatever was spliced together and/or get a jumper harness for the clutch safety switch and the proper female connector for the brake warning light. if you dont have power seats or windows, that big orange accessory wire can stay as is, or use it for something of your choosing.

and yes, for sure check under your dash for the courtesy lights. my 70 firebird "didn't" have them, but when i pulled the dash to do some work what did i happen to find tucked up under there, taped up from the factory?? well, none other than factory under dash lights. untaped them, hooked them up, viola! additional lighting.

[Rob B]

Originally Posted by rolling money pits

seems that way, only variation i'm seeing is with or without gauges according to PY and ames catalogs. the other options were simply add-on harnesses to what's in the factory one. now, that could be nothing more than a "short cut" on behalf of repro harness makers, or what the factory did to achieve the same economies. i was wrong on the power top switch though, just looked at them and the connector for the switch is a three wire. so # 2 is for sure the auto trans kickdown.

youre probably fine with what you have, it's normal, the only things you appear to need is to fix whatever was spliced together and/or get a jumper harness for the clutch safety switch and the proper female connector for the brake warning light. if you dont have power seats or windows, that big orange accessory wire can stay as is, or use it for something of your choosing.

and yes, for sure check under your dash for the courtesy lights. my 70 firebird "didn't" have them, but when i pulled the dash to do some work what did i happen to find tucked up under there, taped up from the factory?? well, none other than factory under dash lights. untaped them, hooked them up, viola! additional lighting.

Thanks for the help!!

[robz]

Originally Posted by Rob B

I have 2 diferrent explanations for #9 and what I think it is possibly for. (the orange and white wire between the radio and steering column) Based on it's length, it has to plug into either a switch on the dash bezel or another harness (that I don't have) right where it's at.

Yes Rob, it plugs into the courtesy lamp harness I showed above and is activated by door jamb switch...

Great to learn about the lighter lamp...Always thought it was fiber optic as mine never burned and looked alot like the ashtray light which is fiber optic...Never took one apart to see...