Soldered mc4 solat connectors

[Rhylsailer99]

I weny to.adjust my solar panel then when I got back inside my boat I noticed the amps had gone from 3amps to around 0.2amps. Could the solder have cracked as there is volts but next to no amps. The battery was drained as I have a fridge running, and the solar panel is a cheap 80w rigid from ebay.

 

[William_H]

I think it unlikely the solder has cracked. However it does seem like you have a failure of wiring or the panel itself.
Start by if possible get a contact to pos output of panel to the pos input to regulator. Should be almost no voltage drop. Do similar with negative supply wire. That should prove or eliminate the Mc4 connection. If all ok put amp meter across the terminals of panel should get 3 amps or more. Try at wiring connection to controller.
Of course controller may have died or decided battery is charged. ol'will

 

[wonkywinch]

If all ok put amp meter across the terminals of panel should get 3 amps or more. Try at wiring connection to controller.

Please don't do this. You are effectively short circuiting the panel, you could damage the panel or the multimeter or blow the fuse inside the meter (if it has one).

The correct way to measure current is to put the meter (on DC current setting with probe plug in correct hole) in series with the load, ie connect one MC4 but put one meter probe into the panel connector, the other into the cable going to the controller. Meter now in series and safely able to measure the current flowing.

I would check the MC4 pins are secure and not being pushed out when you mount the connector instead of sliding fully home to make a good connection.

 

[lustyd]

Please don't do this. You are effectively short circuiting the panel, you could damage the panel or the multimeter or blow the fuse inside the meter (if it has one).

The panel ISC (current short circuit) is measured in this way. It doesn’t damage the panel or the multimeter.

 

[wonkywinch]

I stand corrected. I'm old school and don't go shorting out stuff as it usually goes bang.

Testing solar panel current without frying multimeter

 

[Mistroma]

Please don't do this. You are effectively short circuiting the panel, you could damage the panel or the multimeter or blow the fuse inside the meter (if it has one).

The correct way to measure current is to put the meter (on DC current setting with probe plug in correct hole) in series with the load, ie connect one MC4 but put one meter probe into the panel connector, the other into the cable going to the controller. Meter now in series and safely able to measure the current flowing.

I would check the MC4 pins are secure and not being pushed out when you mount the connector instead of sliding fully home to make a good connection.

Won't series measurement just confirm the low current in the circuit? If there's already a fault in that circuit you'd want to check the panel first and then work through the rest of the circuit.

I thought panels were short circuited when tested to confirm quoted short circuit current. A brief short circuit test would be pretty normal to test a panel.

EDIT
Beaten to it by Lustyd. The danger of not refreshing before posting.