1975 chrysler 75 hp issue

91_james

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Jan 4, 2015
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3
Im having issues gettin my motor to start.

I have no spark and no power to the coil.
Could it be this box i have a mechanic friend that thinks it is.image1.JPG
 
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Frank Acampora

Supreme Mariner
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Jan 19, 2007
Messages
12,004
That year should have a points distributor. Before blaming anything check the condition of the points. If by some chance it has an electronic distributor, check power to the electric eye. There are also two power sources to the black, finned CD box. BOTH must provide power for the CD box to work. There is a red wire and a blue wire going up over the block to the CD box Both must be connected to the respective terminals on the terminal board.

Certainly check the ignition switch. The blue wire on the "I" or "A" terminal should have 12 volts at run or crank position. If the switch was left unprotected from weather, it very likely could be bad.

To test, jump the red terminal on the terminal board (on the side of the engine) to the blue terminal. This bypasses the ignition switch and supplies power at all times to the CD box. Do not leave this attached. It is for test purposes only. It will drain the battery if the engine is left not running for an extended period.
 

91_james

Recruit
Joined
Jan 4, 2015
Messages
3
That year should have a points distributor. Before blaming anything check the condition of the points. If by some chance it has an electronic distributor, check power to the electric eye. There are also two power sources to the black, finned CD box. BOTH must provide power for the CD box to work. There is a red wire and a blue wire going up over the block to the CD box Both must be connected to the respective terminals on the terminal board.

Certainly check the ignition switch. The blue wire on the "I" or "A" terminal should have 12 volts at run or crank position. If the switch was left unprotected from weather, it very likely could be bad.

To test, jump the red terminal on the terminal board (on the side of the engine) to the blue terminal. This bypasses the ignition switch and supplies power at all times to the CD box. Do not leave this attached. It is for test purposes only. It will drain the battery if the engine is left not running for an extended period.



Frank the there is no power getting to the distributor the points are brand new checked the power there is power to the black box thing but no power coming out

also i did the test by bypassing it like you said still nothing

Did find out the coil is bad
 
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Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
There is no power-per-se--going to the distributor. The points go to ground when closed, grounding an internal switching transistor inside the CD box, which signals the CD box to dump its capacitor voltage into the coil. The points and cam regulate the timing of the dump and the rotor position determines which cylinder gets the spark.

Because the distributor body is insulated from the distributor mount and the block by the grease inside the mount, there is a ground wire attached to the body and also attached to the mount using the same screw as the coil ground wire. If this wire is missing or broken the points will not ground and no spark will be generated.

Now: If all is correct and there still is no spark, then it is a good bet that the CD box has failed. They can be repaired but since they are potted with epoxy, it costs as much to repair as buying a new one. First choice would be to see if there is a dealer or junkyard near you with a bunch of old Chrysler engines. You can salvage a CD box from any Motorola ignition 3 or 4 cylinder engine. Occasionally they come up for sale on ebay. I believe that CDI still makes an after-market replacement unit for these CD boxes at a reasonable price.
 
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