68' Help with identifying this dash wire
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Instructor
Joined: Jul 1999
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From: Brick New Jersey
68' Help with identifying this dash wire
Forgive me for double posting this question in both the General and Tech/Performance forums but I am desperate for help with identifying this dash wire. I posted this question a few weeks ago. This time I am attaching a pic with the post. This 12 gauge brown wire with a female black connector is coming from the igition bundle of the wiring harness just behind the ignition switch (68 has the ignition switch in the dash) and gauge cluster. Some members thought it may be wired to a radio noise suppressor but I still don't know for sure. I do have wiring diagrams but I still am confussed to where it goes. I am having problems with my ammeter, seat belt warning light, low fuel and door ajar indicators working and my fuel gauge working correctly on the gauge cluster. Maybe this wire has something to do with energizing the gauge cluster?? I'm giving this issue one more try on my own and with the help of members on the forum before I throw my hands up in the air and bring the car to a shop..... Thanks guys..... I am so frustrated with this issue..... Tom.
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From: New Or-leens Loo-z-anna
My wiring diagram shows that it plugs onto the back of the ignition switch on the terminal that is next to/perpendicular to the pink wire terminal and sends voltage to the firewall then to the brown-white wire that goes to #4 regulator terminal. It also branches off and goes to a couple other areas that I'm not sure about......
but it does seem that it is supposed to receive power from the ignition switch.
If you have an aftermarket ignition switch there is no telling if there is a terminal to plug it onto or not.
but it does seem that it is supposed to receive power from the ignition switch.
If you have an aftermarket ignition switch there is no telling if there is a terminal to plug it onto or not.
2026 Loser of the Year
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From: New Or-leens Loo-z-anna
Melting Slicks
Joined: Oct 2006
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From: Texas
i looked over some sch. i have for a 68, shows brown wire plugging into rear of ign. switch. goes to #4 term. on alterntor. also branches off to another highlighted connection box but is not labeled, but i think its the fuse box. just some fyi.
Drifting
Joined: Oct 2007
Posts: 1,317
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From: Marina CA
There should be a brown 12 ga. wire in the molded connector that plugs onto the ignition switch. That wire supplies power to the fuse block on the ACC side. The loose brown 12 ga. wire in the photo is spliced off of the brown wire in the harness and plugs into a radio noise capacitor. The capacitor is to dampen any electrical pops generated on the ACC side components.
When you turn on the ignition switch that wire goes hot.
In my 68 the capacitor it plugs into is mounted on the backside of the tach.
In the wiring schematic and an oh so ez laminated colored wiring diagram that wire is labeled radio noise conn.
When you turn on the ignition switch that wire goes hot.
In my 68 the capacitor it plugs into is mounted on the backside of the tach.
In the wiring schematic and an oh so ez laminated colored wiring diagram that wire is labeled radio noise conn.
Thread Starter
Instructor
Joined: Jul 1999
Posts: 138
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From: Brick New Jersey
Thanks Guys. With regards to the ignition switch..... I'm pretty sure all the poles to the switch are wired correctly. What I mean by that is.... There are 7 poles in the back of the switch of which only 6 are used. The only pole that is not used is the pole labeled "Grnd" ground. I understand from previous posts that ignition switches were used for several different models of GM cars. NOW.... The pics I have posted are of a new ignition switch I bought and installed but is not correct. If you notice the plastic retaining bars in the pics of the harness plug are in the wrong position. I have since then changed the ignition switch back to the switch that was in the car. I just swapped out the key cylinder and acheived what needed to be done because the key cylinder was worn and rotated with out the key. The female connector on the wire that we are talking about won't fit in the harness plug even if IS to be used on the ignition switch ???? Again..... Still baffled ?????? Thanks, Tom.
Thread Starter
Instructor
Joined: Jul 1999
Posts: 138
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From: Brick New Jersey
My wiring diagram shows that it plugs onto the back of the ignition switch on the terminal that is next to/perpendicular to the pink wire terminal and sends voltage to the firewall then to the brown-white wire that goes to #4 regulator terminal. It also branches off and goes to a couple other areas that I'm not sure about......
but it does seem that it is supposed to receive power from the ignition switch.
If you have an aftermarket ignition switch there is no telling if there is a terminal to plug it onto or not.
but it does seem that it is supposed to receive power from the ignition switch.
If you have an aftermarket ignition switch there is no telling if there is a terminal to plug it onto or not.
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Thread Starter
Instructor
Joined: Jul 1999
Posts: 138
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From: Brick New Jersey
There should be a brown 12 ga. wire in the molded connector that plugs onto the ignition switch. That wire supplies power to the fuse block on the ACC side. The loose brown 12 ga. wire in the photo is spliced off of the brown wire in the harness and plugs into a radio noise capacitor. The capacitor is to dampen any electrical pops generated on the ACC side components.
When you turn on the ignition switch that wire goes hot.
In my 68 the capacitor it plugs into is mounted on the backside of the tach.
In the wiring schematic and an oh so ez laminated colored wiring diagram that wire is labeled radio noise conn.
When you turn on the ignition switch that wire goes hot.
In my 68 the capacitor it plugs into is mounted on the backside of the tach.
In the wiring schematic and an oh so ez laminated colored wiring diagram that wire is labeled radio noise conn.
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From: New Or-leens Loo-z-anna
It looks like Easy Mike and Fordman found the answer.
I have an aftermarket switch also.
As for your big problem with the cluster....I connected an extra ground wire from the metal cluster bezel to the case of the radio/I did the same thing with the wiper dash switch to eliminate the possibility of faulty grounds.
ammeter, seat belt warning light, low fuel and door ajar indicators working and my fuel gauge working correctly on the gauge cluster.
My fuse block had internal corrosion.....when I turned the ign to ON and tapped on the block the gauges would work for a day or two.
My fuel gauge had a faulty ground at the frame near the gas tank.
My door ajar switches weren't closing completely causing the light to stay on.
My ammeter had a bad connection at the voltage regulator.
I think Willcox has a fuel gauge test instructions to determine if the gauge or sending unit is defective.
I have an aftermarket switch also.
As for your big problem with the cluster....I connected an extra ground wire from the metal cluster bezel to the case of the radio/I did the same thing with the wiper dash switch to eliminate the possibility of faulty grounds.
ammeter, seat belt warning light, low fuel and door ajar indicators working and my fuel gauge working correctly on the gauge cluster.
My fuse block had internal corrosion.....when I turned the ign to ON and tapped on the block the gauges would work for a day or two.
My fuel gauge had a faulty ground at the frame near the gas tank.
My door ajar switches weren't closing completely causing the light to stay on.
My ammeter had a bad connection at the voltage regulator.
I think Willcox has a fuel gauge test instructions to determine if the gauge or sending unit is defective.
Drifting
Joined: Oct 2007
Posts: 1,317
Likes: 22
From: Marina CA
Thanks Fordman. I hope your are correct!! Maybe somewhere along the 47 years of this cars life this wire was just left off?? Does the noise reduction capacitor you talk about look the same as the capcitor that is also mounted on the back of the gauge cluster just above the clock?? Thanks, Tom.
The capacitor looks the same as the one near the clock. if I remember correctly it has a different end and is for the clock when it rewinds and the contact points make and break contact so you don't get the popping in the radio.
Drifting
Joined: Oct 2007
Posts: 1,317
Likes: 22
From: Marina CA
There are 2 ignition switches from the era that look the same but the molded connector has the 3 tangs in different places. One is Corvette specific and the other for various passenger cars and trucks.
The ground connection is used I believe for the key buzzer warning on the 68's.
The ground connection is used I believe for the key buzzer warning on the 68's.