Start Button Switch Help...Voltage Drop.

Tynan918

Royal Smart Person
Aug 2, 2021
1,086
63
OK I have this start button switch panel installed in my 1984 Monte Carlo and I'm having trouble getting the start button to work the starter every time I need to start the car. It worked a few days ago and now it's not working... IMG_20220616_135037803_HDR.jpg

The far left switch cuts the power to everything electrical on and off, as you would with the key. The big red circle button powers and engages the starter, and turns over the motor.

Behind, at the on and off switch bottom wire. 12v runs directly to a 12v power source. On this same switch, there is another 12v wire that is powered when the switch is flipped on.

This switch wire is jumped to the upper and lower connections of the starter switch button, which has 12v power with the main power switch flipped on.

On the top opposite side of the start button switch is the wire that runs to the starter "S" terminal on the starter solenoid. This wire is supposed to show 12v when the starter button is pressed and the circuit should be closed when the button is not pressed.

IMG_20220612_102532803_HDR.jpg
IMG_20220611_180936723.jpg


With my multimeter connected at the points that are supposed to show 12v when the main switch flipped on, all show 12v...but the starter wire shows a voltage drop reading 7v when I press the starter button.

All seems good until the 12v power is switched to the starter wire when the start button is pressed...while experiencing this problem, the gauges and radio all power on but dim down when the starter button is pressed.

Starting to think the issue is the starter solenoid wiring running from the starter button to the starter "S" terminal...
 

SSMonteMan

Greasemonkey
Jun 12, 2015
104
43
Long time no see, glad to see your car is coming along.

Battery voltage should be closer to 13v. A reading at or around 12-12.5v is a bad or discharged battery.

A voltage drop from 12 to 7 volts when cranking tells me the battery is bad or heavily discharged or the starter is bad. Usually you'll see a voltage drop from 13v to about 9-10v with a good working starter.
 
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Tynan918

Royal Smart Person
Thread starter
Aug 2, 2021
1,086
63
The "S" wire I have currently is connected by 3-4 different wires from the "S" terminal to the start button switch
Battery voltage should be closer to 13v. A reading at or around 12-12.5v is a bad or discharged battery.
My bad, I should have indicated I'm testing the voltages with the engine off, power on.

Battery and alternator are brand new, not even a week new and have not ran the engine with them either.
 

Tynan918

Royal Smart Person
Thread starter
Aug 2, 2021
1,086
63
A voltage drop from 12 to 7 volts when cranking tells me the battery is bad or heavily discharged or the starter is bad.
Heavily discharged ? Can you elaborate this ?...

Starter may be bad, but other than this no crank issue I haven't had problems with it...
 

SSMonteMan

Greasemonkey
Jun 12, 2015
104
43
Heavily discharged ? Can you elaborate this ?...
A voltage reading below 12.6v, under no load, means the battery is discharged or bad.

Putting a load, like a starter motor, on the battery will draw the voltage down, as it's in use. The voltage drop for a good working starter is usually about 2 volts. If it falls further than that either the load is too great, like a bad starter, or the battery is too weak, like a bad battery.

If you can get the car started, or better yet if you have another car, get the battery to a local parts house, like o'reilly's, and have them test the battery. If it's good do the same with the starter. One of those two are mist likely your issue.
 
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ostrich

Master Mechanic
Aug 27, 2012
292
63
Ontario, Canada
From your pics it looks like from the 12v switch you are stepping down in 'wire' size to the push button switch. You go from yellow crimp on connectors to blue. A yellow gauge wire shouldn't fit in a blue connecter, looks like you have stands not crimped in the blue ones. What happens if you manually connect the 12v switch to the starter wire, basically bypass the push button? Look at your voltage drop. If good I suspect the push button or wiring to it. If there is a voltage drop it's down the line, started, battery etc. eliminate/isolate is the easiest way to minimize things.
 
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mikester

Comic Book Super Hero
Mar 10, 2010
2,646
113
Small town NY
From your pics it looks like from the 12v switch you are stepping down in 'wire' size to the push button switch. You go from yellow crimp on connectors to blue. A yellow gauge wire shouldn't fit in a blue connecter, looks like you have stands not crimped in the blue ones. What happens if you manually connect the 12v switch to the starter wire, basically bypass the push button? Look at your voltage drop. If good I suspect the push button or wiring to it. If there is a voltage drop it's down the line, started, battery etc. eliminate/isolate is the easiest way to minimize things.
Previous posts by the OP on FB showed a video with the wires smoking and getting hot. Not good. Anyone in his area thats willing to help him straighten out his wiring ? Hes got a mess.
 
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