Verifying line output converter

Hi,
I'm trying to troubleshoot my amplifier installation - my old amp was a rockford fosgate 550s, but the wires going to the subs shorted out, and the amp stopped working.

I put my new amp in but didn't hear any sound. I tried measuring the output of my line output converter with a multimeter, but it read 0 volts. I had it in AC mode but there were only two voltage options, 200vac and 500vac. I put it in 200vac mode but I'm not sure if 4 or 5v will even show up then - anyone know?

As an aside, I have a pioneer DEH-8500MP (the line output converter is left over from when I had my stock HU). I remember it being a pain to get out of the car before - the audio shop had to use some special tool. I want to hook up RCA cables to the sub output of it, so I can skip the LOC altogether, but I'm not sure if I'll be able to do that without the special tool.

I would check but before I disassemble the center console / dash area I'd like to know it won't be a complete waste of time to attempt to reach the back of the HU (this is in a 1999 Acura TL btw).

thanks for any input!

Forgot to add, I even checked the levels at the RCA outputs of the LOC while my HU was playing a test tone. I just made a quick 220hz tone at full volume (after reading the forums it looks like I should have used a 1khz tone, but I don't think it should matter too much) that is a minute long, then copied it onto CD 3 times so I'd have 3 mins of 220hz (also did the same thing for 80hz, probably should make it lower for a better sub test tone).

Am I checking the RCA cables correctly? I putting one probe on the outer rim of the RCA connector, and the other probe on the inner prong of the connector. I thought the inner prong was positive but I tried both anyway, and neither of them showed a voltage...

first off you wont be able to measure the output because the car is DC and you had it in AC mode.  Ok your HU has 3 pre-outs built in so you do not need the LOC's you will plug your RCA's direct into your HU.  Now that I read your post again I believe you are asking about pulling the stereo itself out of your dash.  I am not sure of needing any special tools to take your dash apart besides maybe a panel popper which is basically kinda like a bent screwdriver.  I am not to sure about your specific vehicle, but the only thing I could think of needing a special tools to get the stock HU out would be something like DIN removal tools for FORDS or something like that.  I honestly do not think but please dont quote me that you need any "special" as u said tools to remove your HU.  What exactly are you trying to do?  There may be a way around all this fuss.

The car's electrical is DC volts;  the deck output music signal and amplifier music output is AC volts.  Setting your meter to the lowest available voltage range is correct and you will get a valid reading for low voltage if everything is working properly.  Now, how do you know what fried your previous amp?  What short condition did you witness, and how much damage was done as a result of it? 

Note:  it can be dangerous to try reading voltage on the RCAs leading from the deck.  If you touch (short) across the outer neg to the inner pos post with your meter lead you would quickly damage the deck output stage.

Using the low level deck output is certainly superior to using the high level output.  Although with Pioneer sometimes the results can be an uncertainty.  But when using only one set of preouts that uncertainty is lessened.

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