1977 Corvette re-wire
09-24-2016, 04:18 PM
#1
Cruising
Thread Starter
Member Since: Sep 2016
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
1977 Corvette re-wire
Well, hello everyone!
I am jumping back in the saddle with this 77 making a good run at finishing it in under a year. The electrical is the biggest issue, I'd like to tackle that and get it out of the way. I understand BASIC, and very BASIC electrical. I can strip, crimp, splice, twist, and solder with the best of em though.
Pretty much NOTHING on the car is factory, so I can't see spending thousands of dollars on a wiring harness that has fittings I am not going to use or wires I need to add. I will buy them and modify as necessary if that is my best option.
To give you guys a better idea of what were working with here, let me tell you the added items.
ELECTRIC fuel pump, gravity fed, factory sending unit
ELECTRIC water pump
ELECTRIC fans
FACTORY power windows
FACTORY A/C
AFTERMARKET ELECTRIC locks
AFTERMARKET 765 TRANS (HAS SINGLE 12V wire for lock up converter, like a 4l60E)
MSD 6AL ignition
AFTERMARKET TAIL/REVERSE/RUNNING REAR LIGHTS
DIFFERENT FIXED HEADLIGHTS (12V-3 WIRE, HIGH/LOW/OFF) XENON HID BALLASTS
Steering column is the same, gauges, I would love for them to stay factory. However I was shown these dakota digital gauges called VHX. I was informed that these gauges hook up using linked CATV wire, to one central information box where all the sensors hook up. $1,500.00 and the gauges look ok. Its almost double what it would cost to repair factory gauges. I kept the key ignition and seating and carpeting and dash. I wanted to have the exterior look modern sleek amazing, and the inside old muscle feel. I was even considering keeping the working 8-Track in the dash and putting a modern head unit in the car hidden somewhere.
Does anyone have any suggestions as to what wire harnesses I should use for the engine, a/c, rear section, dash?
What do I do for a switch for the headlights, I don't want the high beams on the floor anymore, just a nice functioning switch, how do you connect these fans so they dont stay on all the time, just kick on when need be like newer cars? Water pump on all the time? I have a hard time understanding relays and stuff. I think the water pump was CSR brand and the fans are dewitts brand I believe.
Any help would be greatly appreciated!
http://www.dakotadigital.com/index.c...rod/prd879.htm
I am jumping back in the saddle with this 77 making a good run at finishing it in under a year. The electrical is the biggest issue, I'd like to tackle that and get it out of the way. I understand BASIC, and very BASIC electrical. I can strip, crimp, splice, twist, and solder with the best of em though.
Pretty much NOTHING on the car is factory, so I can't see spending thousands of dollars on a wiring harness that has fittings I am not going to use or wires I need to add. I will buy them and modify as necessary if that is my best option.
To give you guys a better idea of what were working with here, let me tell you the added items.
ELECTRIC fuel pump, gravity fed, factory sending unit
ELECTRIC water pump
ELECTRIC fans
FACTORY power windows
FACTORY A/C
AFTERMARKET ELECTRIC locks
AFTERMARKET 765 TRANS (HAS SINGLE 12V wire for lock up converter, like a 4l60E)
MSD 6AL ignition
AFTERMARKET TAIL/REVERSE/RUNNING REAR LIGHTS
DIFFERENT FIXED HEADLIGHTS (12V-3 WIRE, HIGH/LOW/OFF) XENON HID BALLASTS
Steering column is the same, gauges, I would love for them to stay factory. However I was shown these dakota digital gauges called VHX. I was informed that these gauges hook up using linked CATV wire, to one central information box where all the sensors hook up. $1,500.00 and the gauges look ok. Its almost double what it would cost to repair factory gauges. I kept the key ignition and seating and carpeting and dash. I wanted to have the exterior look modern sleek amazing, and the inside old muscle feel. I was even considering keeping the working 8-Track in the dash and putting a modern head unit in the car hidden somewhere.
Does anyone have any suggestions as to what wire harnesses I should use for the engine, a/c, rear section, dash?
What do I do for a switch for the headlights, I don't want the high beams on the floor anymore, just a nice functioning switch, how do you connect these fans so they dont stay on all the time, just kick on when need be like newer cars? Water pump on all the time? I have a hard time understanding relays and stuff. I think the water pump was CSR brand and the fans are dewitts brand I believe.
Any help would be greatly appreciated!
http://www.dakotadigital.com/index.c...rod/prd879.htm
09-24-2016, 06:22 PM
#2
Race Director
I can appreciate your enthusiasm. BUT...if electrical is not your expertise...then asking for assistance is a good idea.
You have to consider ALL of your electrical components you are adding to the cars system that it DID NOT have it originally.
By knowing the amp draw that these components will draw...will better give you a direction in what wires you need to upgrade...and that may also include your alternator. And what is the possibility that ALL of these new parts and some of the factory ones are all on at the same time. Think of the possible worst scenario (highest amp load) and build your system to those parameters...becasue if you don't...you can possibly run into electrical problems or a wiring system that gets overloaded and can cause a fire.
If your steering column is a 1977 Corvette column...your high beam/low beam dimmer switch is NOT on the floor but you use the turn signal lever to use the dimmer switch.
AS for your cooling fans...need to know what you want them to do. They can come on when the temperature gets to a point becasue you have a sensor in the cooling system that control this...or you can do something else. BUT...need to know what you want.
The water pump should be on all the time while teh engine is running....NOT having it on just does not make sense to me.
AS for all of your other harnesses...it will depend on how adventurous you want to get in this. by the time you get done...TRUST ME...you should have a VERY GOOD knowledge an understanding of wiring...so get ready....there is a lot to learn...but I am sure you can handle it IF YOU WANT TO!
DUB
You have to consider ALL of your electrical components you are adding to the cars system that it DID NOT have it originally.
By knowing the amp draw that these components will draw...will better give you a direction in what wires you need to upgrade...and that may also include your alternator. And what is the possibility that ALL of these new parts and some of the factory ones are all on at the same time. Think of the possible worst scenario (highest amp load) and build your system to those parameters...becasue if you don't...you can possibly run into electrical problems or a wiring system that gets overloaded and can cause a fire.
If your steering column is a 1977 Corvette column...your high beam/low beam dimmer switch is NOT on the floor but you use the turn signal lever to use the dimmer switch.
AS for your cooling fans...need to know what you want them to do. They can come on when the temperature gets to a point becasue you have a sensor in the cooling system that control this...or you can do something else. BUT...need to know what you want.
The water pump should be on all the time while teh engine is running....NOT having it on just does not make sense to me.
AS for all of your other harnesses...it will depend on how adventurous you want to get in this. by the time you get done...TRUST ME...you should have a VERY GOOD knowledge an understanding of wiring...so get ready....there is a lot to learn...but I am sure you can handle it IF YOU WANT TO!
DUB
09-25-2016, 12:06 PM
#3
Cruising
Thread Starter
Member Since: Sep 2016
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
The fans came with a relay kit. But how does that alone kick on if the thermostat doesn't connect to it? There also must be a lead that goes to the A/C system somewhere so it could kick on the second stage correct?
these are the fans....
http://www.dewitts.com/collections/spal-fans/products/spal-dual-fan-kit
thats the fan kit. I also was able to locate both wire harnesses for the new headlamps since they are factory oem lights. I can at least use the pigtail from the harnesses off the back of the lights and solder them into whatever harness I start with. Do I still need a factory 1977 Corvette forward light harness then?
What harness should I start with though? A FACTORY REPRO from like lectric limited or a custom harness? What kind of switch do I use now for the lights? I just want ONE switch, ON, OFF, HIGH
these are the fans....
http://www.dewitts.com/collections/spal-fans/products/spal-dual-fan-kit
thats the fan kit. I also was able to locate both wire harnesses for the new headlamps since they are factory oem lights. I can at least use the pigtail from the harnesses off the back of the lights and solder them into whatever harness I start with. Do I still need a factory 1977 Corvette forward light harness then?
What harness should I start with though? A FACTORY REPRO from like lectric limited or a custom harness? What kind of switch do I use now for the lights? I just want ONE switch, ON, OFF, HIGH
09-25-2016, 06:46 PM
#4
Race Director
The fans came with a relay kit. But how does that alone kick on if the thermostat doesn't connect to it? There also must be a lead that goes to the A/C system somewhere so it could kick on the second stage correct?
I am well aware of these fans. I use them a lot with the DeWitts radiators.
The DeWitts radiators i order ahve a threaded bung in the radiator just below the upper radiator hose. That is where I place a sensor that when the coolant temp gets where I want it ( due to the temp range of the sensor I use AND thermostat temp value) the fans will come on.
SO...the thermostat has nothing to do with the fans coming on...other than making sure the temp value of the thermostat opens so the hot coolant can get the sensor. DID THAT MAKE SENSE?
YES...COOLING FANS COMING ON WHEN THE A/C is REQUESTED this is also a HUGE DEBATE here on the forum and there are different methods of doing this.
Some feel that when the car is sittign still that the fans NEED to be on so the air is being pulled across the condenser so the A/C will work and the high side pressure of the A/C system do not go off the charts and cause for damage.....BUT...many feel that when you are going down the road at speed...the air coming across the condenser is good enough and THUS the fans do not need to be on...or if they are on...they are regulated to half speed. But when you come to a traffic light...they come back on again.
SO...it depends on how you want to do it.
BUT...YES...using the power from your A/C compressor when you turn it on and it begins to operate...this 12 volt power source can be used to activate a relay that will then provide a ground signal to the TWO relays in your fan kit and make the fans come on.
I do KNOW that when I do this..I have tried to only have ONE fan come on when the A/C is turned on..and what I have seen on the gauges is the high side pressure is TOO HIGH...and when I activate the second fan...the system pressure is very good and basically normal. SO...when I do it..BOTH fans come on when the A/C turns on.
thats the fan kit. I also was able to locate both wire harnesses for the new headlamps since they are factory oem lights. I can at least use the pigtail from the harnesses off the back of the lights and solder them into whatever harness I start with. Do I still need a factory 1977 Corvette forward light harness then?
I have to see what you are doing with either you posting the wiring schematic of these new lights...right now I have no clue on what you need.
What harness should I start with though? A FACTORY REPRO from like lectric limited or a custom harness? What kind of switch do I use now for the lights? I just want ONE switch, ON, OFF, HIGH
I am well aware of these fans. I use them a lot with the DeWitts radiators.
The DeWitts radiators i order ahve a threaded bung in the radiator just below the upper radiator hose. That is where I place a sensor that when the coolant temp gets where I want it ( due to the temp range of the sensor I use AND thermostat temp value) the fans will come on.
SO...the thermostat has nothing to do with the fans coming on...other than making sure the temp value of the thermostat opens so the hot coolant can get the sensor. DID THAT MAKE SENSE?
YES...COOLING FANS COMING ON WHEN THE A/C is REQUESTED this is also a HUGE DEBATE here on the forum and there are different methods of doing this.
Some feel that when the car is sittign still that the fans NEED to be on so the air is being pulled across the condenser so the A/C will work and the high side pressure of the A/C system do not go off the charts and cause for damage.....BUT...many feel that when you are going down the road at speed...the air coming across the condenser is good enough and THUS the fans do not need to be on...or if they are on...they are regulated to half speed. But when you come to a traffic light...they come back on again.
SO...it depends on how you want to do it.
BUT...YES...using the power from your A/C compressor when you turn it on and it begins to operate...this 12 volt power source can be used to activate a relay that will then provide a ground signal to the TWO relays in your fan kit and make the fans come on.
I do KNOW that when I do this..I have tried to only have ONE fan come on when the A/C is turned on..and what I have seen on the gauges is the high side pressure is TOO HIGH...and when I activate the second fan...the system pressure is very good and basically normal. SO...when I do it..BOTH fans come on when the A/C turns on.
thats the fan kit. I also was able to locate both wire harnesses for the new headlamps since they are factory oem lights. I can at least use the pigtail from the harnesses off the back of the lights and solder them into whatever harness I start with. Do I still need a factory 1977 Corvette forward light harness then?
I have to see what you are doing with either you posting the wiring schematic of these new lights...right now I have no clue on what you need.
What harness should I start with though? A FACTORY REPRO from like lectric limited or a custom harness? What kind of switch do I use now for the lights? I just want ONE switch, ON, OFF, HIGH
The reason being... there are other lights that need to be on also...and using just one switch...you may find when you do this...may not work...so i would rather you spend the time looking for the switch that will look like you want.. so if you have to go back to a factory headlight switch...at least you tried.
You may also find that you may want to wire in relays for your headlights..and other lights....so the switch you find and use does not have to carry a huge amp load. The switch of your choosing would only be a 'trigger' to activate the relays and make things work.
This is where you will learn on what you NEED to do...but it is all do-able.
DUB
Last edited by DUB; 09-25-2016 at 06:49 PM.
09-25-2016, 11:34 PM
#5
Le Mans Master
Member Since: May 2003
Location: Fernandina Beach FL
Posts: 8,481
Received 3,220 Likes
on
1,732 Posts
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
I have no clue right off the top of my head on what switch to suggest to you and I am not going to look either.
The reason being... there are other lights that need to be on also...and using just one switch...you may find when you do this...may not work...so i would rather you spend the time looking for the switch that will look like you want.. so if you have to go back to a factory headlight switch...at least you tried.
You may also find that you may want to wire in relays for your headlights..and other lights....so the switch you find and use does not have to carry a huge amp load. The switch of your choosing would only be a 'trigger' to activate the relays and make things work.
This is where you will learn on what you NEED to do...but it is all do-able.
DUB
The reason being... there are other lights that need to be on also...and using just one switch...you may find when you do this...may not work...so i would rather you spend the time looking for the switch that will look like you want.. so if you have to go back to a factory headlight switch...at least you tried.
You may also find that you may want to wire in relays for your headlights..and other lights....so the switch you find and use does not have to carry a huge amp load. The switch of your choosing would only be a 'trigger' to activate the relays and make things work.
This is where you will learn on what you NEED to do...but it is all do-able.
DUB
The headlight switch is THREE switches in one-
One part of the switch turns on the parking -and the headlights-
One part dims the gauge lights
And the third part turns the interior lights on and off
I would use the factory harness- and add-on from there. You can use relays for the high current switching and the factory wires to control the relays.
Richard
09-26-2016, 06:16 PM
#6
Race Director
Richard,
GLAD you jumped in on this one.
Two heads are always better than one.
DUB
GLAD you jumped in on this one.
Two heads are always better than one.
DUB
09-26-2016, 06:36 PM
#7
Le Mans Master
One thing not usually mentioned when people here modify the headlights to use relays is the circuit protection. The factory switch has an automatic circuit breaker which trips from high amperage, a safety feature so the headlights will come back on a second or two after it trips. It's very unnerving having the lights go out at speed. An automatic circuit breaker in the supply wire to the relay seems like a good idea.
09-26-2016, 07:02 PM
#8
Race Director
One thing not usually mentioned when people here modify the headlights to use relays is the circuit protection. The factory switch has an automatic circuit breaker which trips from high amperage, a safety feature so the headlights will come back on a second or two after it trips. It's very unnerving having the lights go out at speed. An automatic circuit breaker in the supply wire to the relay seems like a good idea.
that using the headlight switch as it is intended and have the built in circuit breaker go on and off can be a HUGE problem. BEEN THERE!!!!But I am having hard time grasping using another circuit breaker for the headlight relays. It does make sense even though I have to 'sleep' on this one.. Protecting the circuit is PARAMOUNT. I use fusible links or maxi-fuses. And I also have overrides ready to be used to bypass the system if needed if parts fail.
DUB
09-26-2016, 07:14 PM
#9
Le Mans Master
The one time blow circuit protection for the headlights is what I see as a problem, good in most other situations, but could be a death sentence with the light going out permanently on a dark road.
09-27-2016, 06:49 PM
#10
Race Director
If this does occur (lights out at night)...hopefully the owner has the 'smarts' to have a flash light and reflective safety markers they can put out so it will let on coming drivers know they are on the side of the road...out in the middle of nowhere.
And if the circuit has been compromised bad enough the circuit breaker will keep popping....and may take a bit for it to click back on only to pop back off again.
So there is now way to protect this from happening unless NO protection is used...which is CRAZY as we all know....because then the cars wiring can possible catch fire.
No matter what person does when doing wiring and trying to cover all possibilities....there is no way to have all of them work effectively for every scenario.
30+ years of doing this I have yet to have this be an issue...not 'saying' that it can't...total lights out at night while driving...but it just has not happened to me. I have had Corvettes come in that lost ALL power....and the car is literally dead.
So what can we do but hope for the best.
DUB