What happens if I connect the supply terminals the wrong way round?
The supply terminals must not be connected the wrong way round. In the GS740-3P wiring, red is the supply (+) 12V/24V and black is the supply (−)/chassis. Reverse polarity protection is not declared in the product data; there is only a warning not to reverse the connection. For this reason reverse connection carries a risk of permanent damage; verify the polarity by measurement before connecting.
The rule is simple: red to positive, black to negative. Reverse connection is not something to be verified by trying it.
What to do before connecting:
- Verify the voltage and polarity at the battery by measurement; do not trust colour codes blindly, the vehicle's previous wiring may have been altered.
- Fit a fuse of appropriate rating in the supply line.
- Connect the chassis terminal to cleaned metal, not to a painted surface.
- If welding is to be done, disconnect the supply connection.
Not only reverse polarity but also voltage compatibility matters. The GS740 works in the 12V–24V DC range; the GS740-3P, on the other hand, is produced as 12V or 24V according to the order configuration. Do not apply 24V to a system configured for 12V.
If the system does not respond after being energised, measure the fuse first, then the chassis connection and the voltage at the supply terminal. The GS740-3P has a watchdog of approximately 2 seconds; supply interruptions or a loose connection can cause the watchdog to trip; the position the system will take in that case is not stated in the product data.
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