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law32ps87
04-14-2011, 02:55 PM
I have a 1987 prostar 190 that I can't seem to get started. Battery is good, and just replaced the starter solenoid. I have about 12.5 volts on the battery side of the solenoid before trying to start. I have only 9.48 volts on the ignition post of the solenoid with the key turned forward with the buzzer on. When I try starting it just clicks then the buzzer goes away. With the key still turned forward I have 0 volts on both the battery side and ignition post of the solenoid. If i turn the key off, the battery side of the solenoid now only shows 10 volts. I can't try restarting it either unless I take the cables off the battery and then try again. I think there may be something wrong with the wiring from the ignition since the voltage is low but not certain. Someone please help me!

BrianM
04-14-2011, 03:15 PM
I bet its a bad solenoid. Cheap and easy fix.

thatsmrmastercraft
04-14-2011, 04:13 PM
You definitely have a bad connection somewhere - which could be the solenoid. Starting with the basics, does your battery have a full charge? Have you removed and cleaned all the battery connections on both positive and ground sides? Including the ground at the block?

JimN
04-14-2011, 04:56 PM
I have a 1987 prostar 190 that I can't seem to get started. Battery is good, and just replaced the starter solenoid. I have about 12.5 volts on the battery side of the solenoid before trying to start. I have only 9.48 volts on the ignition post of the solenoid with the key turned forward with the buzzer on. When I try starting it just clicks then the buzzer goes away. With the key still turned forward I have 0 volts on both the battery side and ignition post of the solenoid. If i turn the key off, the battery side of the solenoid now only shows 10 volts. I can't try restarting it either unless I take the cables off the battery and then try again. I think there may be something wrong with the wiring from the ignition since the voltage is low but not certain. Someone please help me!

Take your battery in so it can be load-tested. I'll bet it's toast. If the voltage drops to 0VDC with the key in the crank position, either the battery is toast or the bypass wire is broken, disconnected or corroded.

law32ps87
04-14-2011, 05:13 PM
Ill get the battery load tested just to be sure, but I have put my truck battery in there with the same result. I have cleaned all connections including the ground. It is not the solenoid as I have tried the old one, a new one that I had sitting in the garage for a year, and one I just bought at napa today.

What/where is the bypass wire you are talking about Jim?

Thanks

JimN
04-14-2011, 06:45 PM
Ill get the battery load tested just to be sure, but I have put my truck battery in there with the same result. I have cleaned all connections including the ground. It is not the solenoid as I have tried the old one, a new one that I had sitting in the garage for a year, and one I just bought at napa today.

What/where is the bypass wire you are talking about Jim?

Thanks

Points don't live long if they have 12V+ on them, so the ballast resistor is used. With the resistor in place, the points only see about 9.5V and they work fine this way- the voltage they see isn't what the coil uses to cause spark and they're only used to open & close, causing the magnetic field to collapse and this is when the spark occurs. If they had 12V+ on them, they would soon burn but during cranking, the voltage at the points and coil drops enough to make starting almost impossible most of the time and totally impossible if the battery voltage is already low and if you go to the ignition switch to test for voltage in the various key positions, you'll see that the voltage on the RUN wire is cut off when cranking. Also, if you go to the coil, you should see two wires connected to the positive post- one from the ballast resistor and the other from the solenoid's crank post. The voltage still drops when connected directly to this post when cranking, but it drops to about 10-10.5V, which is fine for the short time it takes to crank the motor. When the key goes back to the RUN position, the voltage goes through the ballast resistor again and the points are happy.

Even if the points have been replaced by an electronic ignition system, this wiring scheme stays in place, although some EI module manufacturers recommend removing the resistor.