Ignition/start & other questions-440HP 1970 Chrysler 300

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ppsi

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I have recently restored the entire dash on my 1970 300 convertible. It is an original car with 55K miles. I took out the whole thing and had the pleasure of discovering I routed the harness in wrong so I had to take the instrument cluster out to get it in the right position.
I started the car and it was very hard to start. It had been sitting for nearly a year so I bypassed the gas tank and started it with fresh fuel.
What is puzzling to me is that the engine will crank without starting but when I let off the starter it will fire off. It seems like once it is warmed up and running for a while this is not an issue. It has a brand new Edelbrock Performer carb with electric choke. I had a local garage do the installation which I NEVER do but was getting much heat from the wife to get the car running. Of course they jack legged the linkage and did an overall piss poor job. I don't know what circuit they used for the choke and have not, as of yet, traced this out. I put the edelbrock on to try and solve a problem I had with percolating fuel and no start after driving the car and trying to restart it after about 15 min figuring the fuel was flooding the intake. In general the car runs hot. The Edelbrock didn't help solve this issue so I have added a phenolic 1" spacer under it. Could the viscous coupling on the fan be shot?
I also replaced the original starter which makes a huge difference in cranking the motor.
I have the FSM for the car which was a must but it shows a lot of wiring that is for optional equipment which had me chasing my tail on a few items. I also did the amp meter/bulkhead connector bypass modification. I did a Mopar electronic distributor/orange box several years ago.
I was thinking that maybe the ballast resistor was wired wrong but it is correct.
Any ideas on where to look for this "delayed start" issue is greatly appreciated.
 
ppsi said:
I have recently restored the entire dash on my 1970 300 convertible. It is an original car with 55K miles. I took out the whole thing and had the pleasure of discovering I routed the harness in wrong so I had to take the instrument cluster out to get it in the right position.
I started the car and it was very hard to start. It had been sitting for nearly a year so I bypassed the gas tank and started it with fresh fuel.
What is puzzling to me is that the engine will crank without starting but when I let off the starter it will fire off. It seems like once it is warmed up and running for a while this is not an issue. It has a brand new Edelbrock Performer carb with electric choke. I had a local garage do the installation which I NEVER do but was getting much heat from the wife to get the car running. Of course they jack legged the linkage and did an overall piss poor job. I don't know what circuit they used for the choke and have not, as of yet, traced this out. I put the edelbrock on to try and solve a problem I had with percolating fuel and no start after driving the car and trying to restart it after about 15 min figuring the fuel was flooding the intake. In general the car runs hot. The Edelbrock didn't help solve this issue so I have added a phenolic 1" spacer under it. Could the viscous coupling on the fan be shot?
I also replaced the original starter which makes a huge difference in cranking the motor.
I have the FSM for the car which was a must but it shows a lot of wiring that is for optional equipment which had me chasing my tail on a few items. I also did the amp meter/bulkhead connector bypass modification. I did a Mopar electronic distributor/orange box several years ago.
I was thinking that maybe the ballast resistor was wired wrong but it is correct.
Any ideas on where to look for this "delayed start" issue is greatly appreciated.
Click to expand...


I would hope you are farmiliar with a voltmeter! The ballast resistor is bypassed while cranking by the igniton switch. You have two circuits in the ignition switch, when the key is in the run position (Ign. #1) it feeds battery voltage to the ballast resistor which feeds the coil a reduced voltage while running to make it live a longer life. When you have the key in the cranking position (Ign. #2) the ignition switch feeds the coil full battery voltage. (Or it's supposed to if working correctly.)

You need to check battery voltage while cranking, it should be the same voltage as what you see on the coil + while cranking!
 
I am under the impression that even if the ballast was bad the car would start but then die because I2 is out of the circuit and I1 is on the other side of the resistor. I am quite familiar with a voltmeter. I can even use an ohmmeter but I generally use a multimeter :). I will check these voltages today.
Thanks-Howard


nothingbutdarts said:
I would hope you are farmiliar with a voltmeter! The ballast resistor is bypassed while cranking by the igniton switch. You have two circuits in the ignition switch, when the key is in the run position (Ign. #1) it feeds battery voltage to the ballast resistor which feeds the coil a reduced voltage while running to make it live a longer life. When you have the key in the cranking position (Ign. #2) the ignition switch feeds the coil full battery voltage. (Or it's supposed to if working correctly.)

You need to check battery voltage while cranking, it should be the same voltage as what you see on the coil + while cranking!
Click to expand...
 
Is it possible that the people who installed the electric choke powered it from the wrong side of the ballast?

The huge, ongoing problem with all these old girls is the BULKHEAD CONNECTOR. Lots of high--current wiring goes through there (you already did the bypass) but the ignition feeds (1 and 2) etc, headlights, go through there as well.

I would CHECK the voltage on the blue IGN 1 feed. Your basic path is ---from the bypassed ammeter---to the connector on the ign switch, through the switch, back out the ign switch connector, and through the bulkhead. Any of these connections, including the contacts in the (old?) switch can cause voltage drop.

The easy way to check voltage drop is to NOT go back and forth between sources, but to actually check it under load. So with the engine running, stick one probe right directly onto the battery positive post, and the other probe onto a terminal served by the blue ign 1 wire. You are looking for a very low reading the LOWER the better, zero being perfect. If you read more than about .2 (two tenths) of a volt, you have a drop in the above mentioned circuit path.

(A drop here will also cause overcharging [overvoltage] because the regulator ign/ sense terminal will think the battery is low)

While we're at it, you can check the regulator ground the same way. With the battery up and engine simulating low / med cruise, stab a probe right on the bat neg. post, the other on the regulator case. Once again, zero is perfect, no more than .2V or so. If more you have poor ground to the regulator.

Your starting issue suggests that ign2 (resistor bypass) is not happening in start. ONLY way to check this is to either have two people or some means to clip leads to the ballast IGN terminal.

Put one probe on the IGN terminal, other on the battery. Since in start the ign switch is supposed to be providing "resistor bypass" through IGN2, once again you should read a LOW voltage WHEN CRANKING and ONLY when USING THE KEY for start.

To put it another way, check voltage to ground at the IGN terminal when twisting the key to crank......

and then recheck the voltage to ground AT the battery. There should be very little difference in voltage, but this time perhaps as much as half a volt or more is acceptable because of the high starter cranking current.
 
While you are working on diagnosis, a quick and acceptable workaround is to run a wire to the coil (+) terminal from either end of the wire that runs from the starter relay to the starter. This way you'll have line voltage to the coil while (and only while) cranking, which is what is missing right now.
 
slantsixdan said:
While you are working on diagnosis, a quick and acceptable workaround is to run a wire to the coil (+) terminal from either end of the wire that runs from the starter relay to the starter. This way you'll have line voltage to the coil while (and only while) cranking, which is what is missing right now.
Click to expand...

and of course, THIS

!!! LINE VOLTAGE !!! ???

Would that be 220, or 221, Dan? (whatever it takes)

How to tell if you're running WAY too much power:

You need 3 phase service to your hamshack

Your service meter has grease zerks

Everytime you press the "push to talk" a huge "bang" follows as all the switchgear engages

Your wattmeter has 2" hardline fittings

You "key up" your handheld and the antenna gets warm

You "key up" your handheld and the antenna gets RED

When you talk, the water in the toilet bowl fluctuates

You need an amplifer to drive the BIG amplifier

The PA needs a diesel generator---power line just can't supply the amperage

You "unkey" and the receiver won't recover for 5 seconds--all the circuits are just in saturation

You mess up the neighbor's TV sets when they're turned OFF

You can't operate CW because noboday makes a key with contacts "that big."

You unkey and hear your own voice echo three times as it "comes back" around the world
 
67Dart273 said:
!!! LINE VOLTAGE !!! ???
Click to expand...

Line voltage. Meaning, whatever voltage is present across battery + and ground (or alternator B+ and ground).

Would that be 220, or 221, Dan? (whatever it takes)
Click to expand...

Only on the floor models! :toothy10:

How to tell if you're running WAY too much power:
Click to expand...

You say "Hey, honey, would you switch on the lights for me?" and this is what the neighbours see when they look in your back yard:

[ame="http://www.youtube.com/watch?v=xspo3Xxb8No"]YouTube - Awesome Transformer Arc[/ame]
 
Yes indeed it was an issue with the start wire to the Ballast resistor. In my case it is a 14awg brown wire. I put a meter on the coil while cranking and got milivolts so i went to the resistor figuring the last dude to hack on the car did something but there was continuity to the coil from the resistor although there was a shabby splice put in for some unknown reason which I got rid of. I was visually chasing wires and couldn't see anything wrong until I shrunk my head (yes my head can get even smaller than usual) and got a look at the bulkhead connector and saw the brown wire was in the right terminal spot but had backed out of the connector about 1/4". The bulkhead on this car is so hard to get to and manipulate. With the 10awg ammeter connector bypass the wires are drilled right through 2 of the connectors and this makes moving the connectors even more difficult. I also replaced a lot of the harness tape that was nasty with the OEM style, non adhesive type and I wish I had waited to do this because it wold have made tracing the wires soooo much easier. I did leave some slack in the bypass wires and the holes are drilled large enough so the wires slide through the connector but they are thick & stiff so it was a nightmare getting the plugs to clip securely. Actually getting the plugs to clip in was a real PIA-just no room to gain leverage. I removed the spade terminal from the plug and opened the barb on it and stuck it back in and checked for voltage and had it although only about 10.75 during cranking? I've seen other posts talk about the voltage at the coil being low during cranking due to battery load while cranking. Is this something I should concern myself with. The battery is not old and it has not presented any problems?
Thanks muchly for the great help.
Any ideas on my heat problem or should I see if the spacer does the job?

Howard
Hampstead, NC
 
ppsi said:
checked for voltage and had it although only about 10.75 during cranking?
Click to expand...

Yup. That's normal.

I've seen other posts talk about the voltage at the coil being low during cranking due to battery load while cranking.
Click to expand...

Exactly. Line voltage drops when load is applied; cranking is a heavy load. You'd see the same ~10.75v across the battery itself during cranking.
 
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