Getting 9v from IGN2

[Canadian1968]

Hello everyone, new to the board. Also part of dodgecharger.com but cant seem to get help to this question.

Without turning this into a novel i will just tell ybaou my current problem.

During cranking i am only getting 9.5V to my brown wire at my ballast connector. This is supposed to have 12V or close to it , which is sent to my coil for start up , as well backfed threw ballast to power ecu.

Now if i disconnect power to the starter and just run power to my fuseable link, i get 11.7 V to my brown wire.

With starter connected again i tested brown wire at the back of the ignition switch i get 9.5V at crank. Testing only between battery terminals i get 10.7V during crank.

So why am i getting such a big voltage drop.

The car is 68 Dodge Charger with MP electronic ignition upgrade. Upgraded dual feild alternator and electronic regulator. New engine wiring harness, and coil.

thank you

 

[nothingbutdarts]

Ignition switch or bulkhead connections??

Do a voltage drop test along all wires going into and out of the car on the ignition circuit.

it also sounds like your battery is very weak or a large draw on it while cranking.

Older engine? Compression?

What is the "problem" that has you looking at all the voltages?

 

[Canadian1968]

We installed the MP conversion kit last year. THe car was running very well. Near the end of the year I noticed that the fusible link was cooked at the bulkhead and was causing obvious electrical problems. I rigid it up so I could drive th car to its winter storage place, we also installed a brand new battery just before we put it in the garage ( so battery is new !)

I had purchased a new wiring harness from Evans wiring and new bulkhead main connect as it was damaged from fusible link., also a new eletronic voltage regulator to go with the new ignition. In order to use regulator correctly I purchased a new 2 FLD alternator.

Everything put in I got the car to start, but wasn't charging and would not idle, I found that my regulator had a poor ground and got the car to charge at 13.5V at approx 1000RPM. The car woudl still not idle. I rememberd that I had for to hook up my vaccum lines that run to the headlight switch. I got under dash and plugged those in. Ever since I have not been able to get the car to start again. I do not have spark coming from my coil . I have a new ECU and multiple resistors, but those do not seem to be the problem .

I dont' think I am getting enough voltage to activate my ECU and start the car, hence why I am hunting this down !!

 

[nothingbutdarts]

What is battery voltage with nothing turned on?

To just try to get it started, you can run a jumper wire from the battery + to the coil + and see if it starts with the key and idles OK. This bypasses all the internal car wiring. If it won't start this way I would check grounds to the ECU. (you should double check this anyway).

 

[Canadian1968]

if I jump the coil that will give me 12v to the coil, but I still need to get 12v to the ECU do i not??? and right now I won't get that threw the key. ECU is grounded with an 8awg ground.

 

[nothingbutdarts]

if I jump the coil that will give me 12v to the coil, but I still need to get 12v to the ECU do i not???( You need more voltage to the coil when starting the car to get a good spark.) and right now I won't get that threw the key. (OK, you could jump both sides of the ballast resistor with battery voltage, that would put full battery voltage to the ECU if it's wired correctly) just to see if it will start.) ECU is grounded with an 8awg ground.

This procedure is just to see if it will start and run. You still need to fix the problem.
Do you happen to have another electronic dist.? It could be a small block or big block one or know where to borrow one? If you do you could just plug it into the harness and spin it by hand to see if you are getting spark for trouble shooting purposes.

Take the good old digital voltmeter and do a voltage drop test over the ignition switch. (red lead to the power terminal of the switch and black lead to ign. 1, then to ign. 2 while cranking and see what voltage drop is on these two circuits.
For that matter, while the meter is out hook the red lead to battery + and the black lead to the ignition switch power in terminal, turn the key on and see what kind of drop you are getting on that circuit. (Just my 2 cents)