Complete Rewire Project

[Indycars]

Sorry for the delay, got tied up. The schematics are pretty busy with dash circuits, etc. looks like you have it under control now anyways.

Not a problem, you have no obligation to solve my problems.

 

[roadmonster]

No ignition switch on the column. GM had them in '66, but the gov't gave Chrysler an extra year so my '67 which came from a Chrysler Imperial does not have it.

To use the trailer harness, just use the existing taillight wires for relay signals, with relay output through the harness to a terminal strip. As many lights as you want will all have 12v. The old column signals will usually work, but the brake wire circuit sometimes does not. Better to just skip the column for your brake signal. I use a low-pressure brake switch to a relay, to the harness, to a terminal strip, to 6 brake lights. The harness allows normal stop/turn/tail functions no matter what you hook up and you can easily change things around.

 

[Indycars]

Eventually I would like to get confirmation on all my drawings, so here is the next one for the "Power and Charging" circuits.

The numbers next to each alternator connection is the wire gauge. Let me know what you think, will it work???

 

[PotvinGuy]

Looks good. Some minor points: the relay in the switched power circuit would probably smoke and melt before the 100 amp fuse blew. I'd replace both of those 100 amp fuses with something closer to the expected loads. Make sure the relay can handle the amps you will need. Most of the cheap auto relays are only good for 30-40 amps. My car is wired much like yours and I have lots of electrical loads and use a 50 amp relay. The alt light circuit doesn't need a diode. The S and L leads on the alt carry tiny current, so 16 or 18 or 20 gauge is fine. And I would wire the anti-theft switch to the ACC post on the ignition switch.

 

[ellis8500]

Two things: Fuse ratings seem too high for the expected loads. I have 40 amp main fuse and with everything on I'll never get there. Calculate maximum load and add 25% for fuse rating. Remember, the fuses are to protect the wiring so they don't burn up and start a fire. Amp load rating on a wire depends on gauge and length. Find a table that shows that relationship on the net and go from there. Also, you need a relay for the starter solenoid. You do not want the ignition switch to handle the surge current as the solenoid engages; it can be over 100 amps for a very short time. You probably do not need the relay for the switched power load. Some use them some do not since those loads seldom come close to the ignition switch ratings. Just my observations and experience. Others will chime in I'm sure.

 

[Indycars]

Looks good. Some minor points: the relay in the switched power circuit would probably smoke and melt before the 100 amp fuse blew. I'd replace both of those 100 amp fuses with something closer to the expected loads. Make sure the relay can handle the amps you will need. Most of the cheap auto relays are only good for 30-40 amps. My car is wired much like yours and I have lots of electrical loads and use a 50 amp relay. The alt light circuit doesn't need a diode. The S and L leads on the alt carry tiny current, so 16 or 18 or 20 gauge is fine. And I would wire the anti-theft switch to the ACC post on the ignition switch.

Good point about the relay. Once I get all my drawings done, then I can decide what size fuse to replace those 100 amp babies with.

I thought the diode kept the alternator feeding back thru the system and keeping the engine running. Is that not so in this case???

The wire size will never be smaller than 16 AWG for two reasons:
1.) I can't afford 100 feet of every gauge in every color, so to minimize inventory, 16 AWG will be the smallest.
2.) Anything smaller than 16 doesn't fit my terminals well and 18 & 20 are just too fragile to work with.

What do you gain by moving the anti theft switch to the ACC side of the ignition switch?

 

[Indycars]

Two things: Fuse ratings seem too high for the expected loads. I have 40 amp main fuse and with everything on I'll never get there. Calculate maximum load and add 25% for fuse rating. Remember, the fuses are to protect the wiring so they don't burn up and start a fire. Amp load rating on a wire depends on gauge and length. Find a table that shows that relationship on the net and go from there. Also, you need a relay for the starter solenoid. You do not want the ignition switch to handle the surge current as the solenoid engages; it can be over 100 amps for a very short time. You probably do not need the relay for the switched power load. Some use them some do not since those loads seldom come close to the ignition switch ratings. Just my observations and experience. Others will chime in I'm sure.

I do have a electric fan and the alternator is a CS-144 capable of 175 amp. You ask why so high...... well the fan is going to be marginal in 100°F stop & go traffic and I want MAXIMUM air flow when the alternator is at it's lowest output (idle 850 rpm). That was the biggest output fan that would fit.

My starter circuit will be 1/0 cable and about 6 feet long. Yes I already have a table I'm using.




I thought the solenoid is a type of relay, so no 2nd relay would be needed. What' wrong with my thinking???

 

[ellis8500]

Using 16g as the smallest size is fine. You can always go bigger on wire. The fan power should connect direct to battery, with it's own in-line fuse and a relay. The temp switch turns relay on-off. Relay coil power thru fuse block connected to switched power. On attached drawing I relocated the neutral start switch to the ignition relay circuit. I have Ford alternator so it will be a bit different than yours. Note that electric choke is tied to the S term of alternator that supplies 12v when engine is running. I do not know what the S term does on yours. I have body and engine harness connectorized so I can remove body without having to "Unwire" anything.

 

[Indycars]

Using 16g as the smallest size is fine. You can always go bigger on wire. The fan power should connect direct to battery, with it's own in-line fuse and a relay. The temp switch turns relay on-off. Relay coil power thru fuse block connected to switched power. On attached drawing I relocated the neutral start switch to the ignition relay circuit. I have Ford alternator so it will be a bit different than yours. Note that electric choke is tied to the S term of alternator that supplies 12v when engine is running. I do not know what the S term does on yours. I have body and engine harness connectorized so I can remove body without having to "Unwire" anything.View attachment 11067

I'm using a Flex-A-Lite 31163 variable speed and temperature adjustable fan controller. It has a 40 amp inline MegaFuse.
https://www.flex-a-lite.com/accesso...roller-with-thread-in-temperature-sensor.html



Good idea for the neutral safety switch, less current for it to handle.

My "S" terminal is the voltage sensing wire. Yes I like and want a connectorized harness. What connector did you use, weatherpack or deutsch or ......???

I have removed the electric choke and all linkage. Had to remove it so I could install a TPS for the AQ-1 data logger. Didn't seem to need it anyway so far for 60°F and up.

 

[ellis8500]

I used Amp connectors. Part No. of one shown on drawing. These are not rated weatherproof but are fuel/oil resistant. My car is a fair weather vehicle so didn't feel the need for Weatherpack or that rated connector. I won't even drive it on wet streets.

 

[roadmonster]

Here is an easy improvement while you're rewiring. Marine terminal strips with 10-32 studs make ideal distribution blocks for power and ground. 12ga wires direct to battery. Makes everything easy and allows for future expansion. The plastic cover has been removed from the ground strip to show the studs.

 

[fletcherson]

Eventually I would like to get confirmation on all my drawings, so here is the next one for the "Power and Charging" circuits.

The numbers next to each alternator connection is the wire gauge. Let me know what you think, will it work???

View attachment 11064

I have a software program around here somewhere called electronics workbench that allows one to build circuits, test, and print them. I haven't used it in a while, but it would be good for someone interested in designing harnesses, etc and printing them for future use or distribution. I used it when I was enrolled in Devry back in 98. If I had it loaded, it is easy to print schematics and the like. I keep an old pc to use old software, but haven't used any of it lately. if you can't get it working with the info you have, I can put a schematic together if you want, but it looks like you got things under control. My experience with older cars is that if you plan to use lights that require much amperage, you should use relays, because the old switches wont tolerate much heat, especially the turn signal switch that the brake, signal, and flasher lights go through.

 

[PotvinGuy]

About the diode; I could have been clearer. If you use the ACC post for switched power, and put the ignition on the IGN post, then you don't need the diode. The diode is just to keep power from getting from the alternator to the ignition, causing the motor to keep running. I put all the things needed to run the motor (ignition, EFI, electric fuel and water pumps) on the IGN post, and everything else on the ACC post. This way you can play the radio, turn on lights, etc without powering up all the stuff needed to drive.

Are those Blue Sea fuse blocks? That's what I use!

 

[PotvinGuy]

And I run a big cable from the alternator case to the battery negative terminal. Don't like to depend on any part of the car for ground, especially when talking about really big amps.

 

[PotvinGuy]

Two tips: 1) Never post just after a nap. 2) I don't like any big currents going thru the ignition switch, so I use relays for the switched power, the ignition and the starter circuit. 3) Never post just after a nap....

 

[Indycars]

Two tips: 1) Never post just after a nap. 2) I don't like any big currents going thru the ignition switch, so I use relays for the switched power, the ignition and the starter circuit. 3) Never post just after a nap....

I have another tip ..... never post after 2-beers, 1-margarita and 2- glasses of red wine.

I will respond tomorrow with a clear heart and a sound mind to all the responses above.

Thanks guys and gals!!! -PC

 

[roadmonster]

Yes, PotvinGuy, Blue Sea blocks. Guess you had that good idea before me. I've seen your very clean wiring system. Nice. Mine is designed with lots of extra capacity and loose wires so in an emergency you can just reroute any circuit to a spare fuse. Fan, lights, and horns have a remote fuse block up front and audio has a remote block behind the seat.

 

[Indycars]

Here is an easy improvement while you're rewiring. Marine terminal strips with 10-32 studs make ideal distribution blocks for power and ground. 12ga wires direct to battery. Makes everything easy and allows for future expansion. The plastic cover has been removed from the ground strip to show the studs.

Noted ...... thanks!

 

[Indycars]

I have a software program around here somewhere called electronics workbench that allows one to build circuits, test, and print them. I haven't used it in a while, but it would be good for someone interested in designing harnesses, etc and printing them for future use or distribution. I used it when I was enrolled in Devry back in 98. If I had it loaded, it is easy to print schematics and the like. I keep an old pc to use old software, but haven't used any of it lately. if you can't get it working with the info you have, I can put a schematic together if you want, but it looks like you got things under control. My experience with older cars is that if you plan to use lights that require much amperage, you should use relays, because the old switches wont tolerate much heat, especially the turn signal switch that the brake, signal, and flasher lights go through.

I hope it doesn't come to that, but if it does ........

 

[Indycars]

About the diode; I could have been clearer. If you use the ACC post for switched power, and put the ignition on the IGN post, then you don't need the diode. The diode is just to keep power from getting from the alternator to the ignition, causing the motor to keep running. I put all the things needed to run the motor (ignition, EFI, electric fuel and water pumps) on the IGN post, and everything else on the ACC post. This way you can play the radio, turn on lights, etc without powering up all the stuff needed to drive.

Are those Blue Sea fuse blocks? That's what I use!

Thanks for explaining the diode, that even makes sense to me!

Yes I've settled on the Blue Sea 5026 ST like the photo below except with a cover. I'm going to have two of them, one for Switched Power and the other for Constant Power. That gives me plenty of room for expansion with 24 circuits.

http://www.amazon.com/gp/registry/wishlist/2YFIUJ8JWFA6F/ref=cm_wl_sortbar_o_page_2?ie=UTF8&page=2

https://www.bluesea.com/products/5026/ST_Blade_Fuse_Block_-_12_Circuits_with_Negative_Bus_and_Cover

And I run a big cable from the alternator case to the battery negative terminal. Don't like to depend on any part of the car for ground, especially when talking about really big amps.

Noted, thanks!