Bypassing ballast resistor / Operation (1 Viewer)

[bhsdriller]

Have been having a no-start issue all of a sudden. Can I bypass the ballast resistor and wire the 12v switched right to the + on the coil?
Reason I ask is I tried it and the cruiser started right up but ran super rough. Wouldn't idle at all and then died

I have also read about people putting 12V right from battery to positive on coil? What do you do with the 12v switched when doing this?

Wiring isn't stock but is all correct as follows:
- 12v switched to ballast resistor and the other side to the + on the coil
- negative side on coil has the stock wire going to the distributor and that little thing on top of the coil (condenser?). There is also what looks like a condenser on the side of the distributor

 

[fjwagon]

If you suspect the rough idling is caused by the components mentioned above. First I would ohm out the resistor and same goes for the condenser except your multimeter may not have the capacitance option to check the condenser. Usually a condenser will cause it to run rough if it's bad and eventually take out you points. So if I had to shot gun it that would the first component I would replace.. As far as removing the the resistor I would not do that if it was fine before you started have problems. The resistor limits the current coming from the coil. Sometimes resistor is inside the coil. When you remove it, the circuit will have a lot more current and that is not good.

As I always say check your components separately and replace if bad. The other is clean you terminals. Do a visual check for frayed or broken wires. I will say sometimes they may Check good, however, they fail under a load. These are cheap components compared to having a mechanic troubleshoot it and send you the bill. I hope this helps.

 

[bhsdriller]

@fjwagon thanks. Still digging into it and trying to test things. Is that condenser on the coil mount stock? It also has one (or at least looks like one) on the distributor.

It's a new issue, cruiser has ran perfect since i've had it. Sat for a couple weeks and now just cranks and cranks without even trying to start.
Bypassing the ballast resistor let it start finally but idle rough as mentioned.

 

[pithicus]

Points gap could be miniscule if it's been there forever. Coil could be failing too. It's normal for a condenser to be on the dizzy, often in the dizzy. The PO could have slapped on the extra condenser when the other one was going bad, and never bothered to remove the original. Not sure if two condensers wired together would effect the spark if one of them failed?
Good luck.

 

[73FJ40]

@bhsdriller .

Miles/months/years since last tuneup? (points, condenser, plugs)

A condenser on the coil may be for radio noise suppression. If so, I don't know offhand if it's supposed to connect to + or - terminal.

I sincerely recommend you get a plastic cap for the side + battery terminal before a dropped tool sets off a fireworks display.

 

[fjwagon]

I did notice the condenser on the coil and almost said it needed to be relocated to the the dizzy. But now that you mentioned there is one already there. I would check each component and verify all is well. You may have faulty coil under a load. Also check the wiring is good. Make sure you have no arcing. Sometimes checking it in dark may help. If so use silicon as a temp fix.

The reason the condenser is at the dizzy is because it's most efficiently dispersing its spark to the the spark plugs. It packs a little punch if you what I mean every time a spark is generated. The stronger the spark the Spunkier the response.....to a certian point of course. That's why some will convert over to an electronic set up. It's more dependable but really a better spark at the spark plug.

 

[Steamer]

Have been having a no-start issue all of a sudden.

the cruiser started right up but ran super rough. Wouldn't idle at all and then died

If you haven't already, I'd confirm that the idle solenoid is functioning. You should hear it "Click" when the key is turned to "Run"

 

[4Cruisers]

I did notice the condenser on the coil and almost said it needed to be relocated to the the dizzy. But now that you mentioned there is one already there. I would check each component and verify all is well. You may have faulty coil under a load. Also check the wiring is good. Make sure you have no arcing. Sometimes checking it in dark may help. If so use silicon as a temp fix.

The reason the condenser is at the dizzy is because it's most efficiently dispersing its spark to the the spark plugs. It packs a little punch if you what I mean every time a spark is generated. The stronger the spark the Spunkier the response.....to a certian point of course. That's why some will convert over to an electronic set up. It's more dependable but really a better spark at the spark plug.

A step up from a condenser in or on the distributor, without going to fully electronic ignition, would be to install a 1/75 through 8/76 igniter at the coil.

 

[bhsdriller]

@bhsdriller .

Miles/months/years since last tuneup? (points, condenser, plugs)

A condenser on the coil may be for radio noise suppression. If so, I don't know offhand if it's supposed to connect to + or - terminal.

I sincerely recommend you get a plastic cap for the side + battery terminal before a dropped tool sets off a fireworks display.

Not since i've had it ~2 years. I actually have stuff for a tune up coming in so will see what happens.
Will do on the battery

 

[bhsdriller]

Idle solenoid is working fine.

Have a condenser coming in with the points and stuff for the tune up so i'll remove both these and start over with one at the distributor.

 

[pjohnson]

Check your coil also. The ballast resistor drops the 12v to about 9v to the coil. Running it with 12v may have damaged the coil. Probably not, but easy to check.

 

[bhsdriller]

Ok so did some testing after work.

Ballast resistor was hard to get a solid reading from. Bouncing around but would give 1.5 - 3.5 ohms when I could.
Other times giving me 0.0 or 0L

Battery voltage - 12.3v
Key on into ballast resistor- 11.6v
+ on coil after resistor - ~6v

I have 3 coils here (stock, oreilly and Napa) and tried testing them with the below method. None of them produced a spark out of the high voltage wire. This is with a new wire also so ruled that out.
"Pull the center high voltage wire fromt he distributor and hold it 1.4 inch from the block. Disconnect the wires at the - side of the coil. Turn the ingition key on and then momentarily ground the - side of the coil and see if you get a spark."

 

[bhsdriller]

Coils are reading:

1) 0.7 ohms on primary
13.5 k ohms on secondary

2) 1.6 ohms on primary
8.11 k ohms on secondary

3) 1.4 ohms on primary
8.76 k ohms on secondary

 

[pithicus]

With a points system , The first thing I check when it starts misbehaving is the points, especially if the points have been there for some time. Over time the gap gets smaller and eventually closes completely, and the engine runs erratically or not at all. It takes 5 mins to check the gap. Apologies if you already checked the points. I hate points personally.

 

[bhsdriller]

Oh yeah so I did check them and they were good at the 0.018

 

[fjwagon]

The ballast resistance should be around 1.3-1.7 ohms according to the oem. Should not be jumping around. Disconnect one side. Make sure it's a solid connection. I use a small wire brush to remove the oxidation and dirt.

 

[fjwagon]

Points: And the rubbing block gap should be 0.3 mm ( 0.012 in)
And the dumping spring gap should 0.1-0.4 mm (0.004-0.0016 in)

 

[fjwagon]

It's easier to show the diagram. When checking the secondary coil resistance it should between the + and high tension terminal.

The spark plug wire should be less 25k ohms. I hope this helps.

 

[fjwagon]

Coils are reading:

1) 0.7 ohms on primary
13.5 k ohms on secondary

2) 1.6 ohms on primary
8.11 k ohms on secondary

3) 1.4 ohms on primary
8.76 k ohms on secondary

Number 1 primary is too low.
Number 2 and 3 secondary are low.

 

[bikersmurf]

I’d start by replacing the points and condenser. They can be set with feeler a gauge or Dwell meter.

Standard coils are designed to run on about 8 volts. The ballast resistor brings voltage to 8 when running. It is bypassed when the engine is cranking to counteract the drop in voltage due to the starter load.

Bypassing the coil will send 12v to it which will cause it to overheat and/or fail.