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Relay "ignition wire"

S

Shuboxlover

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Quick question guys...I think it should be an easy one. :)

I am wiring up a fan relay and a fuel pump relay on my 69 Roadrunner. I'm not a total idiot, but was wondering if I could hook up the "ignition" wire from the relays (so the relays come on when the key is in start/run position) to the positive side of the coil...I am not very familiar with MOPAR ignition systems, and don't know if MOPAR drops the voltage at the coil or not. Does the voltage stay a constant +12VDC on the positive side of the coil whether you're starting the car and/or once it's running?

If this will NOT work, where is an easy place to pick up 12V when the key is turned to start/on.

Thank-You!!!
 
NO...... if you have a ballast resistor on your ignition system, you will only get about 8 volts at the coil in the "run" position.

YES...you will get 12 volts BEFORE the ballast resistor coming from the ignition switch in the "run" position.
 
Thanks tpodwdog!!!! That's what I was wondering!

So can I hook the "ignition" wires from the relay coil to the "in" side of the ballast resistor? Or is there a better place to run them? BTW I have a 4 pin ballast resistor....it's upgraded to electronic ignition.
 
Shuboxlover said:
Thanks tpodwdog!!!! That's what I was wondering!

So can I hook the "ignition" wires from the relay coil to the "in" side of the ballast resistor? Or is there a better place to run them? BTW I have a 4 pin ballast resistor....it's upgraded to electronic ignition.
Click to expand...

if it were me..i would run a home run directly from the fuse box. just get your test light out and find a open fuse that operates in the "key on" position

OR...get your test light and put it on the drivers side of the ballast....then turn the key on and see if it lights up. theres 2 wires going in right there...one of them is from the ignition switch.

wiring is tricky especially if youre running a high drawing fan. you gotta watch what else is on that circuit or youll keep blowing fuses.i would run a home run (dedicated line) from the fuse box....alot safer....then make sure ya got a good ground at the rad support.
 
Don't forget good ground, proper fused power source, nice tight sealed connections with as few splices as possible and use the right gauge wire depending on your amp draw. Make sure your wires all have a clean run where they dont rub, pinch, or get too much heat exposure. Rubber gromet through the firewall etc. Almost all cars that burn have fuel or electrical related issues. Don't cut corners and good luck.
 
THANKS GUYS!!!!!!!!!!!!!!!!!

EXACTLY WHAT I NEEDED!!!!!!!!!!!!!!!!

I will home run the two "ignition" wires. I always overkill wires, 12awg on both these relays, I have a circuit breaker on the fuel pump and a fuse for the fan. I am SOOOOOOO close to firing this thing up...but want to make sure I have all my bases covered!!! Once my throttle linkage stuff comes in (4 weeks) :( it should be ready to roll...


THANKS SO MUCH!!!!!!!!!
 
I,m installing efi in my 68 Bee and using the brake warning lamp 12 volt feed to power the computer and pump relay as voltage present during keyed start and run,same feed to ballast from key switch .
 
All right.....more questions on this.....

I am SOOOOOO close to firing this thing up I feel like a kid at Christmas!!!!!!!!!!!! But I want to make sure everything is correct. I installed the battery today and went slowly installing each fuse one at a time. The entire car is rewired with harnesses from Year One....I was going to home run the fuel pump and fan
"ignition" wires to fuse block, but this is what i found. Please tell me if this is correct and advise me what to do.

photobucket-4213-1362016928638_zps24ce12d3.jpg

Starting from the right (3A fuse)

3A INST LPS......................No voltage whether the key is on or not (VERY puzzling)
20A TAIL LP C-LTR..............battery voltage always
20A DOME STP E/FLASH.......battery voltage always
20A RR-A/C ACC..................battery voltage ONLY when key is in run position
20A A/C HEAT......................battery voltage ONLY when key is in run position
7.5A B/UP RADIO.................battery voltage ONLY when key is in run position

SO, I guess my first question is, What's up with the 3A fuse not having any power ever?

2) How could i hook my fuel pump (especially) and my fan relay to ANY of these fuses. It appears that I either have 12V ALL the time on fuse 2 & 3 (from the right) or 12V ONLY when the key is in the run position (0V when the key is in the crank position) at the other fuses (aside from the 3A)

I hope this all makes sense, if I wasn't clear enough, please ask and I'll do my best to answer them.

Thanks!!!!!!!!!
 
on the back of that fuse block , there SHOULD be a blade to accept your connectors. being that its a year one unit...i dunno if it has those or not. (i have blades all over on my '70 RR....69 shouldnt be all that different )

see what your fuel pump draws as far as amperage....and connect to appropriate fuse.

same with the fans

if that isnt doable....tap into something that you either dont have.....like air conditioning (a/c) or rear defogger (r/r)

to get power (12v) to your elecrtic fuel pump during cranking...you MIGHT have to tap on the drivers side of the ballast where 12 volts are present during cranking. (youll want the electric fuel pump pumping on crank)

ABSOLUTE LAST RESORT............... tap fuel pump directly into the battery positive(+) on a switch.
 
O.K....That's what I was thinking....There is spades on the back of the block. I will run the fan relay "ignition" wire to the fuse block in spot 5 (from the right, with a 3A fuse in place of the 20A), because it doesn't need to be on when cranking. I'll run the fuel pump relay "ignition" wire to the full power side of the ballast resistor so it is on while cranking.

One more thing though....when am I supposed to get power to the 3A fuse (1st position on the right)? Is something awry, or is this normal?

Thanks
 
not sure about the 3 amp fuse....do you HAVE the dash lights working?....if they are working. theyre probably on a unassigned fuse. turn on the dash lights and start pulling fuses. when you pull one that makes the dash lights go out....its on THAT fuse.

dash lights are on a "voltage limiter"....thats the small rectangular silver box on the dash circuit board. it reduces voltage to THE DASH LIGHTS from 12 volts down to 5 volts only on the twist in lights connected to the circuit board.
 
I turned the headlights on, they work, taillights work, horn works, dome light works. Turn signal indicators, high beam light, brake light all work in cluster work....but I don't think the "back" lighting work....IDK, I'll have to do some more investigating.

OH, one other thing....which side of the 4 pin ballast resistor have full battery voltage? Is it the side with the blue wires, or the other side?
 
its the wire that comes from the bulkhead connector TO the ballast...usually on the DRIVERS SIDE of the ballast....the wire on the PASSENGER SIDE of the ballast is DIRECT 12 VOLT SHOT OF POWER TO THE COIL ON cranking....i.e....it bypasses the ballast ONLY during cranking to start the car easier.

not sure of the color but i want to say the blue one. just get your friend " mr. test light" , and he will tell you !

*addition*...perhaps for you to fully understand....i might need to explain in detail what your ignition switch, and the ballast resistor, and the coil do in conjunction with eachother.

IGNITION SWITCH : has 3 major positions...1. off...2. start....3. run
start and run both deliver 12 volts in their perspective positions.....heres the difference. in START...it delivers a full 12 volts directly to the coil to make it easier to start a cold engine BYPASSING THE BALLAST RESISTOR .. RUN delivers 12 volts also...but it delivers it to the "in" side of the ballast ( thats the drivers side of the ballast). when in RUN...and going into the ballast...the ballast cuts the 12 volts down to around 8 volts and sends that 8 volts to the coil from the PASSENGER SIDE of the ballast ....this is so you dont burn the coil out when youre driving for hours on end....so...you should have 2 (two) wires coming from the bulkhead connector to the ballast.START wire goes on the passenger side of the ballast....RUN wire goes to the drivers side of the ballast.

so when you put the key in the ignition and turn it all the way to the right, you are delivering 12 volts to the coil.......when the car starts and you let go of the key and it springs into the RUN position you are in escessence delivering only 8 volts to the coil AFTER it runs through the ballast resistor.when you turn the key to OFF...you are cutting all power to the ballast resistor.

FOLLOWIN ME HERE ?
 
That's the first time I've ever seen someone have a "banned" under their name.

Wonder what the offense was???
 
That's the first time I've ever seen someone have a "banned" under their name.

Wonder what the offense was???
Click to expand...

Take the word "offense", and turn it into a plural, add in some on and offline colorful discussions and there you will find the answer.
 
696969 said:
That's the first time I've ever seen someone have a "banned" under their name.

Wonder what the offense was???
Click to expand...

Sad story,
Something escalated, wrong things said.
Too bad.
But it is what it is...
We have RULES here on this forum.
Move on...these arent the Drods we are looking for.....
 
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