wiring help

[1BadRS]

If you have seen any of my other posts I am in the process of putting my 84 bronco ii back together. The motor is back in the truck and I'm wiring everything up right now for the duraspark conversion.

Here is my question. I have everything wired up except for the (+) positive side of the coil and the red wire on my duraspark box. The previous owner cut up the engine harness so this is the one wire I am not sure which one to use. The bundle of wires on driver side firewall has a bunch of wires that get power when the ignition switch is in the run position but do not get power when in the start position. Don't those wires need power in both run and start? Everything else is good to go.

Thanks,

 

[enginepaul]

Some things are cut out during start so that you can get full power to the starter - and a full 12 volts to the coil.
During the run mode, you may have one wire that is producing 9v - that would be the + to the coil when running.

 

[1BadRS]

I'm using a TFI 12 volt coil if that matters with no resistors.

I was using a test light at first but just put my volt meter on the wires. When my key is in the run position each of the wires get a full 12 volts. They all go to 0 volts when I put the key to start position.

Please correct me if I'm wrong but doesn't the (+) positive wire for the coil, as well as the duraspark box need to be hot in both start and run?

 

[enginepaul]

"doesn't the (+) positive wire for the coil, as well as the duraspark box need to be hot in both start and run? "
Yes - sounds like you need to find the wire that is live during start; try looking at a wiring diagram to make it easier.
Many people run the coil with the full 12v and they say there is no problem with longevity.

 

[kimcrwbr1]

If you can find the red/ltgreen wire that is the one you want for both the coil and the red to the module. Then you can tak and splice the start wire from the start solenoid back to the white on the module. Are you using the stock TFI coil you can use battery voltage. If you need the ballast resistor for the coil wiring is a little different.

 

[1BadRS]

I'm using a stock TFI coil so I can just run 12 volts to it.

I saw that red/ lt. green wire in the wiring diagram they have in the tech section. I do not seem to have that wire at all in my engine bay. I checked every wire possible and the ones that have 12 volts in the run position get no power when I put it in the start position.

Inside the truck at the ignition switch I can find wires that get power with the key in start but not in run. I'm really at a loss here as I can't find one single wire that has power in run and start but no power with the key in the off position :icon_confused:

Can I tap into the one wire that is hot in start and another that is hot in run? or can I just run power to these at all times even in the off position?

 

[kimcrwbr1]

you could put a diode in the start wire to the ignition and coil so it gives them both power in start but after you let off the key the power dont go back to the start solenoid

 

[1BadRS]

That is a really good idea given my current situation. I'm not well versed in electrical so would you be able to recommend the right one I would want to use? Once I have the correct diode I can make something like this

http://cgi.ebay.com/JSB-Haydex-12-volt-Hydraulic-pump-diode-wire-/330462239373?pt=LH_DefaultDomain_0&hash=item4cf1159a8d

Thanks for the help and Happy New Year to all

 

[kimcrwbr1]

I believe there is one in the original computer wire harness if you have it you just put 12 volts to one side then the other to see which way the power flows. I would think any part store would have one or maybe radio shack. I`m guessin 20 amp would be ok but higher would be better. I know guys use them to give the coil 12 volts with a ballast resistor for quick starts to bypass the resistor.

 

[kimcrwbr1]

My schematic says it is on the dkgrn/wht wire

 

[kimcrwbr1]

Actually it says wht/pnk on one side and dkgrn/wht on the other side of the diode