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Discussion Starter #1 (Edited)
How it Works

If the hood of the car is open when you start the car the AutoStop-Start is disabled even if you close the hood with the car still running.
The circuit feeds the starter voltage to the hood switch to do this. The 680 ohm resistor provides the correct voltage at the switch (7.8 volts) and the diode is just to protect from the starter flyback spike. (Fig 1-2)

NOTE: These instructions are for a 2018-2019 Equinox. It may work for other models/years if the same type of hood switch is used. The relay location may be different. (If you do this to an earlier model please add to the instructions.)

Parts needed

-680 ohm (1/4 or 1/8 watt resistor)

-Diode 1A 400V (IN4004 or equivalent) Just used for protection so high voltage is important.

-9 ft thin wire with thin insulation, at least two colours
I used 30 gauge Teflon coated it needs to be very thin to fit in the connectors or you will need to strip the ends thinner.

-Shrink tubing or electrical tape to insulate.

Assembly

-Twist and solder the Cathode (white band) of the diode to the resistor (Fig3)

-Cut three, 3 foot pieces of wire (2 ft is probably enough)

-Twist and solder the wires to the free end of the diode, resistor and the junction.
NOTE: Make the junction wire colour lighter than the diode wire (Fig 4)

-Fold the diode (Anode) wire back so it is on the same side as the junction wire (Fig 5)

-Cover the connections and the circuit with heat shrink tubing or just tape it all up so nothing shorts. (Fig 6-7)

-Take the cover off the front driver side fuse box in the engine compartment and lay the circuit on it (Fig 8)

-Route the double wire to the hood switch and trim. (Fig 9)

-Strip about 1/4 inch off the two wires.

-Unplug the hood switch (Note the red locking tab needs to be slid back before you can squeeze the release tab) (Fig 10)

-Insert the two wires in the connector holes and fold back (Dark wire to Black and light wire to Yellow) (Fig 11)

-Re-connect. (This is where thin wire helps the fit) (Fig 12)

-Back at the fuse box unplug relay K05 (Fig 13)

-Shorten the single wire and strip back about 3/4 inch of insulation.

-Wrap a loop around Pin 87 of the relay (Fig 14)

-Plug the relay in. The fit is tight enough to secure the connection (Fig 15)

-Put the cover back on the fuse box and you are done.

Troubleshooting

The weakest part of this design are the thin wires used to make the connection. Doing it this way avoids the need cut and splice into the cars wiring harness but the wires are fragile.

The most unreliable connection is the one under the relay.

If you have problems remove the light colour wire from the hood switch and connect to a volt meter. When you start the car you should see 12 volts there for a second or two. If not check the connection under the relay again.
 

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Awesome! Thanks for the instuctions.
 

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Great idea and write up! :grin: I knew there should be a simpler way to disable Stop/Start.


I envisioned using something like a 555 timer circuit to supply a momentary open on the hood switch. But this is even simpler.


One suggestion. Perhaps larger sized (18ga?) and thicker insulated wire might be used up to the point of the switch and under the fuse cover. Then splice/solder or wire crimp a smaller diameter wire a short length before connecting to hood switch and connections under the fuse box.
That way, the wires run to the connection points would be a little more robust. Teflon insulated wire is great, but thin wires might get snagged and broken somewhere along the line.
 

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Discussion Starter #5
Updated instructions

Seems I am locked out of editing my previous instructions so here is a new copy for now.

I modified them slightly so the tricky hidden connection to the relay is checked before you move on.

I may make further modification in the future if problems are found but the design wont change much.

10 Cent Auto Stop-Start Disable Circuit

How it Works


If the hood of the car is open when you start the car the AutoStop-Start is disabled even if you close the hood with the car still running.
The circuit feeds the starter voltage to the hood switch to do this. The 680 ohm resistor provides the correct voltage at the switch (7.8 volts) and the diode is just to protect from the starter flyback spike. (Fig 1-2)

NOTE: These instructions are for a 2018-2019 Equinox. It may work for other models/years if the same type of hood switch is used. The relay location may be different. (If you do this to an earlier model please add to the instructions.)

Parts needed

-680 ohm (1/4 or 1/8 watt resistor)

-Diode 1A 400V (IN4004 or equivalent) Just used for protection so high voltage is important.

-9 ft thin wire with thin insulation, at least two colours
I used 30 gauge Teflon coated it needs to be very thin to fit in the connectors or you will need to strip the ends thinner.

-Shrink tubing or electrical tape to insulate.

Assembly

-Twist and solder the Cathode (white band) of the diode to the resistor (Fig3)

-Cut three, 3 foot pieces of wire (2 ft is probably enough)

-Twist and solder the wires to the free end of the diode, resistor and the junction.
NOTE: Make the junction wire colour lighter than the diode wire (Fig 4)

-Fold the diode (Anode) wire back so it is on the same side as the junction wire (Fig 5)

-Cover the connections and the circuit with heat shrink tubing or just tape it all up so nothing shorts. (Fig 6-7)

-Take the cover off the front driver side fuse box in the engine compartment and lay the circuit on it (Fig 8)

-Unplug relay K05 (Fig 13)

-Shorten the single wire and strip back about 3/4 inch of insulation.

-Wrap a loop around Pin 87 of the relay (Fig 14)

-Plug the relay in. The fit is tight enough to secure the connection (Fig 15)

-Check the resistance to ground on the loose end light wire. It should be about 680 ohms.

-Wiggle the wire at the relay and check that it is not intermittent. (Since it is hidden this is the most unreliable connection.)

-Route the double wire to the hood switch and trim. (Fig 9)

-Strip about 1/4 inch off the two wires.

-Unplug the hood switch (Note the red locking tab needs to be slid back before you can squeeze the release tab) (Fig 10)

-Insert the two wires in the connector holes and fold back (Dark wire to Black and light wire to Yellow) (Fig 11)

-Re-connect. (This is where thin wire helps the fit) (Fig 12)

-Put the cover back on the fuse box and you are done.

Troubleshooting

The weakest part of this design are the thin wires used to make the connection.

The most unreliable connection is the one under the relay. It is also possible that the wires break when the hood switch connector is plugged back together.

Using thicker wires and splicing into the harness will be more reliable but it will be harder to remove if you bring the car in for warranty.
 

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Discussion Starter #6
OOPS. Now that the weather is colder I started getting 'Low Hood Switch" voltage trouble light.

Looks like when the starter is not engaged and the voltage drops it pulls the switch voltage low through the resistor. To fix this I had to add one more diode in series with the resistor so it only pulls up the voltage up and not down.

This fixes the problem of the trouble light and still my car has not auto stopped for a few months now.

I will update this thread when I get the chance.
 

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OOPS. Now that the weather is colder I started getting 'Low Hood Switch" voltage trouble light.

Looks like when the starter is not engaged and the voltage drops it pulls the switch voltage low through the resistor. To fix this I had to add one more diode in series with the resistor so it only pulls up the voltage up and not down.

This fixes the problem of the trouble light and still my car has not auto stopped for a few months now.

I will update this thread when I get the chance.
Might need a trim pot for the resistance.
 

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Discussion Starter #10
The diode fixed the problem . No codes for a few weeks. Should have realized with the starter off it would pull the voltage low with out a diode.
 
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