Wiring ideas for your car

Discussions about general body work and modifications
lavron
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Re: Wiring ideas for your car

Post by lavron »

tomb22 wrote:Did you come up with a fuse panel for your car Mike?
Yes I have 2, 10 circuit boxes that look like this.
Image

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
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Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

tomb22
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Re: Wiring ideas for your car

Post by tomb22 »

I made up 2 wiring harnesses under the hood going to the fire wall connector. One going along the drivers side fender to lights and cooling fans, the other going to the motor for coil, starter, electric choke, water temp gauges. I'm assuming your fuse boxes will be inside the car?
tom
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lavron
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Re: Wiring ideas for your car

Post by lavron »

tomb22 wrote: I'm assuming your fuse boxes will be inside the car?
Yes, they do have water proof covers but I would be more comfortable with them inside. I am thinking of doing them like Lou suggested and having one box as an accessory box, or ignition on box.

Trying to think of what needs key off power, maybe like the cooling fans? And headlights/taillights are usually that way. I don't think I will have anything that needs power to maintain any kind of memory like a radio. I mean I am going to have the disconnect on the negative side so no worries about battery drain while the car is parked, I will just shut off the ground.

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
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Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

lavron
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Re: Wiring ideas for your car

Post by lavron »

Not sure I should post this here but it is about my wiring harness and I have never made an electrical category :roll:

This really is not a necessary item but I have been looking for the plug that connects my DS1 to the ignition box, well I aim looking for a pigtail, I know they made on to the ignition module boxes but thought someone might sell just a pigtail.

I have seen DS2 pigtails but my plug is different, it looks like this;
Image
If you are wondering what is different, the little ears for the plug to clip on with are on the top and bottom in this picture, all the others I have seen they are 90 degrees to this (would be on the sides)
I have seen some (MSD) that look like they would plug on but are just 2 wires not 3, I can't even find a picture of a ignition box that matches this :roll:

My other option is cutting this plug off and putting Weathertech style fitting I just wanted it easy if I ever needed to switch out the distributor (I am doing the HEI controller BTW)

I don't know I guess I would have a hard time just pulling the distributor and swapping in a DS2 if it became necessary anyway because my plug wouldn't match :roll:

I said I was "converting" (quoted because there was never anything there to convert, it is a new install :roll: ) to use the HEI module instead of the DuraSpark module and I know they suffer from heat failure, some have said to mount them inside the car, I was thinking I might do that and keep the engine bay a little less cluttered, just was wanting opinions on if everyone thinks it would be better there or fine out in the engine bay. I am going to add the heat sink to the HEI module and if I can find them I have some piezo coolers (not a fan) off an old computer that are 12 volt I might throw one on there. The reason I am going to use the HEI module is they are cheap and readily available, I can keep a spare or two in the car if I ever have a failure.

I stole this picture from out on the internet but added the text on how to do this mod, if anyone is interested. Its shown with a heatsink attached (Amazon has them for around $10).
Image

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

lavron
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Re: Wiring ideas for your car

Post by lavron »

Here is a picture I had up on my computer desktop that might make the HEI conversion more clear, again not my picture :roll: I am probably going to wire like this one is with the relay.

Image

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

lavron
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Re: Wiring ideas for your car

Post by lavron »

Correct me if I am wrong, but I was looking up how to install the newer style starter in my car (Ford mini starter, 98 mustang I think) Anyway with this I eliminate the fender mounted solenoid correct?

Here is a wiring diagram I picked up off the web.
Image

Like this but I think the relay is only for neutral safety switch.

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

tomb22
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Re: Wiring ideas for your car

Post by tomb22 »

You are correct. Using the mini starter eliminates the solenoid on the fender. If I remember you are going to have a clutch pedal, so you need to have a switch on the pedal so when the clutch is depressed the switch is closed. Then run the start wire from the keyed switch thru the clutch switch to the starter.
tom
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lavron
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Re: Wiring ideas for your car

Post by lavron »

I made a first stab at mapping out my Main Engine Run Harness, I may have a few questions :roll:

Image

First this is what each sub circuit does (kinda by the relays)
RELAY 1 - When IGN is turned on it activates a certain number of fuse circuits in the fuse box (Ign On) - Those are; Fuel Pump Relay 3, Coil & ICM Relay 2, Oil Pressure Switch, Fuel Pump Relay 3, Temp Switch Relay 5 ground.
RELAY 2 - Is also activated when IGN is on supplying 12V to the ignition system (is this relay even required?).
RELAY 3 - Activates supplying power to fuel pump if there is oil pressure, otherwise Oil Pressure Switch will supply power to the pump if the starter is activated (not sure how to prime the pump yet)
RELAY 4 - Supplies ground if the clutch pedal is depressed activating the relay to the start circuit (I think this needs a power wire to it for activate?)
RELAY 5 - Supplies ground to Temp Sensor/Switch so fans will only run with ignition on (not sure they should not be able to run after car shut off?)
That is what each relay does, there are also two big fuses/circuit breakers in the main power line from the battery and between the alt and the starter (not sure the second one is needed?)

Main questions right now; The ACC is hot when the car is running (IGN ON) correct? If so I was going to make the ACC terminal on the ignition switch activate a relay to power the ACC circuits in the fuse box(es).

Also how do you prime the fuel pump, do I need another circuit to do that?

Is Relay 2 needed or is it redundant and Relay 1 is already doing that?

I put it up there earlier on Relay 4 needing a hot wire run to it so it will work, could the starter wire (from ST terminal) supply the power it needs so it only activates when the starter does?

Probably more stuff I have missed on this, let me know or ask any questions if something is not clear. This is just the harness to make the car run I will do more for the other circuits/systems, probably do a lighting system harness and an accessory harness for stuff like the A/C and air compressor etc.

EDIT: I wondered about adding an Inertia Switch into the fuel system like this one https://www.amazon.com/Inertia-Vehicle- ... pons&psc=1

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

tomb22
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Re: Wiring ideas for your car

Post by tomb22 »

Hi Mike
Pretty nice wiring diagram. ACC should be hot when Ignition is on and you can use a relay to feed the ACC circuits. If you want the oil pressure switch to control the fuel pump, you need a time delay relay to allow the oil pressure to come up. I turn my fuel pump on when the ignition is on directly but I do have a inertia switch in series and you should too. My fuel pump runs low pressure and has its own control built in.
I would eliminate relay 2
The wire from the start position on your switch is only hot when you have the the key turned to start position. I would take that wire thru your clutch switch and then directly to the starter. Eliminate relay 4 and the wire going to the oil pressure switch from the ST position.
Hope this helps
tom
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lavron
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Re: Wiring ideas for your car

Post by lavron »

Thanks Tom, I just started looking at the fuel pump setup and was basing my wiring off of this illustration I found out on the web.

Image

They had that center terminal running to the starter wire I was not sure what the purpose was unless it was to kick the pump on without oil pressure when you were in the start position? I will figure the inertia switch in as well.

The only reason I decided to go with the electric pump (Carter P4070 - 4-6 PSI Pump) was to run a return fuel system through a regulator (Summit SUM-220058 adj 1.5-25 psi) taking it down to around 3 psi which is what the carbs are supposed to like. The Summit regulator has three outlets plus a gauge port and the inlet & return ports (hard to find a return style regulator below 4.5#) so I can use it as a distribution block as well running a line to each carb.

After I got that wiring diagram uploaded I was looking at it and thought what purpose does relay 2 serve :roll: because relay 1 is already doing that.

I have been sitting tonight making another wiring diagram that shows where all the circuits tie in and to which box (lights, A/C, etc.) I was thinking of getting 100 amp relays for two that supply the fuse boxes (there are 200 and 300 amp relays as well) I figured it would not hurt to have them oversized. I also changed so one box was split between IGN on and always hot and the second box is all ACC even though I don't have many accessories mostly just heat/air and the air ride compressor, with the individual fuse connection I can do any combination I need I guess.

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

lavron
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Re: Wiring ideas for your car

Post by lavron »

I have been looking for a pigtail to fit this Clutch Safety Switch. It is a Standard Motor Products NS157, not sure what it originally fit or if it is universal, it measures approx. 1/2" square and has a two pin connector.

Not sure but it came in a Intermotor branded box (still Standard Motor) so maybe a foreign car fit.

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It is not a completely vital component (I never had one before) but thought it would be a nice safety feature while I am doing all this work.

I may have to just solder a couple of wires on to it or find some really small blade connectors, it will be up under the dash so I am not too worried about moisture.

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

tomb22
Posts: 513
Joined: Thu Jan 28, 2016 7:11 pm

Re: Wiring ideas for your car

Post by tomb22 »

Your fuel pump diagram will work if you want your pump to shut off when there is not enough oil pressure. I had to look it up, but the switch works like this. The contact between S and P is normally closed, so when you turn the key to start the current goes to the starter and fuel pump relay. When the engine starts and oil pressure comes up the switch changes, so now the set of closed contacts are between P and I. Current is now going from the Ignition switch to to the fuel pump relay.

I installed a Holley 7 lb low pressure fuel pump that shuts off when pressure is reached. I also ran it thru a mechanical regulator with a gauge to turn it down to about 5 lbs. I did not install a return line and it seems to work just fine. The fuel pump regulates itself. I'm feeding a Holley 4 barrel carb.
tom
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popscomet
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Re: Wiring ideas for your car

Post by popscomet »

we have those switches on our race cars,,,cause we run lectric fuel pumps,,,low oil pressure kills the gas ...have a wreck motor dies kills the gas flow....stood in the pits one night and watched a race car burn to the ground,total loss...just cause that fuel pump keep feeding the flames....even tho motor was dead.....pop
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pop/glenda

lavron
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Re: Wiring ideas for your car

Post by lavron »

popscomet wrote:stood in the pits one night and watched a race car burn to the ground,total loss...just cause that fuel pump keep feeding the flames
That is why I am doing it, probably from a suggestion you or someone on here made. The Inertia switch is a similar item to shut down fuel if the car was ever hit and the motor kept running.
tomb22 wrote: I did not install a return line and it seems to work just fine.
I have been reading that the return line helps on keeping the carb settings consistent and keeps the fuel cooler to avoid vapor lock and boiling fuel etc. I think I need all the help I can getting and keeping the three carbs to running evenly.

I have modified the wiring diagram to make the changes, added the inertia switch in the relay ground for the fuel pump, eliminated relays 2 and 4, put a circuit breaker in the main line, changed the configuration on the fuse boxes and added heavy duty relays for 1 & "new" 2.

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I could move the cooling fans to Ignition On side of fuse box but later might want to figure out a way to run the fans with the car off like modern ones do but not sure it would be necessary.

Sometime I will give more detail on how the relays are going to be wired etc so this will make more sense :roll:

Need to get my wire ordered and a few more parts that I haven't gotten yet but need to figure out my wire sizes next.

See Ya,
Mike
64 Comet 202 Sedan, My first car, I have owned it since 1979!
Image
Performance rebuild on a BUDGET - Installed; 250-6, T-5, 8.8 LSD, MII, Air Ride - Whatever I do it will be awesome!

tomb22
Posts: 513
Joined: Thu Jan 28, 2016 7:11 pm

Re: Wiring ideas for your car

Post by tomb22 »

Looks good Mike except the inertia switch. It should be between relay 3 and the fuel pump and no ground wire. I'm sure you would have found this, but I thought I should point it out.
Have a great day
tom
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