How do you test the RCA sub outputs on your head unit?

[Danish16461]

k so I did the whole thing on that link you posted for testing the Ohms between the shields and the Headunits' case and I'm getting no response on my meter... I'm assuming this means the fuse inside the HDU connecting the shields to the case at some point blew? Well I'll have to try and do the fix that the link suggested and see if that works... also in that diagram are you suppose to put a fuse on the line connecting the shields to the case or is just grounding the two shields to the case with a wire enough?
Don't want my car catching on fire =p
Thanks for all your help so far on this btw!

[Danish16461]

ok well after all that work sodering etc still nothing... grrr I guess this means the RCA jacks blew out on my head unit? I'll have to check the warrenty cause I got it at best buy like 3 years ago so not sure if its still covered etc... =(

[Perry Babin]

To confirm that the meter is working properly, if you touch the probes together, does the meter read ~0 ohms?

[Danish16461]

Yup my meter works fine... sigh... guess I better start looking for a replacement head unit... =(

[Perry Babin]

With the meter set to AC volts and the output as high as you can set it without risking damaging the speakers connected to the head unit, do you read any AC voltage with one probe on the RCA shield and the other touching the center conductor inside the RCA jack?

[Danish16461]

I only get 0.006 flowing through there, once in a while would peak at 0.046 but thats as high as it went on any of the RCA jacks... guessing thats a bad thing since they didn't even reach 1 volt? and usually they're 2-4v lines right?

[Perry Babin]

That would seem to indicate that there is no output. Are you 100% sure that you were making contact with the internal contacts? Sometimes they're simply two small contacts and difficult to hit. Plugging in a known good set of RCA cables and measuring the voltage on the other end of the RCAs may be easier.

Try the same test across a pair of speaker wires to confirm that the meter is working properly.

If you have access to another head unit, try reading AC voltage on the other head unit's RCA outputs.

[Danish16461]

Yea, I tested them again with the RCA cable connected and didn't get anything out of the cables on any of the RCA's... Oh well, I'm already getting a replacement headunit so no worries... hopefully this time it will work. Thanks for all your help though! I've deffinitly learned a thing or two from all this at least. =)

[Perry Babin]

Your current head unit was likely damaged when a 12v source/wire made contact with the RCA shields. If you let the same thing happen with the new head unit, it will be damaged as well. The damage can occur in a fraction of a second.

[Danish16461]

so basically just make sure that the battery is unplugged during the whole install process and don't reconnect it until everything is set up and installed... Well thanks for your help with all this!