Pioneer head unit cycling on/off?

[EivlEvo]

Howdy folks...

I just picked up a Pioneer headunit to install in my 87 (thats right) Volvo 240.

I ordered the wiring harness from Crutchfield. It turned out to have the correct wires, but the wrong plug. I soldered the harness from the headunit, to the crutchfield harness, and then snipped the end, and soldered the wiring to the original Volvo harness.

I clicked the car into acc, and it prompted me for setup. I obliged. I go and start the car, and it's doing it's thing (changing colors and what not), and appears to be functioning just fine as I'm paging through the manual.

Then I selected source to the FM tuner, and the speakers came on (with static) but then the headunit turned off for about 1 second, then on (in the same mode) for 1 second (no speaker noise) and just kept cycling this way endlessly.

I turned off the car, and suspected perhaps I had a bad ground. I had the ground wired into the factory harness as I assume it's grounded somewhere logical. But I clipped it, and mounted it to a suitable grounding location. This caused the headunit to react the same way, and then just ultimately go dark... so I'm assuming that I should go back to my old ground, but... where does that leave me with the cycling display?

Anyone have any thoughts?

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[mlstrass 5,000+ posts]

Try temporarily running 12v directly from the batt, so you know the signal is good. Might be a bad HU...

 

[cfox10 10+ year member]

What type of unit is this? I know someone who had a model with the steering wheel input on the back (same size/look of the 3.5mm aux jack) and plugged a cable into it which ended up causing it to go crazy and turn on and off.

 

[EivlEvo]

Squad:

I actually found out what was happening just last night.

The BACKplate on the HU had disconnected itself from the box, and was only allowing the faceplate to make an intermittent connection.

I repaired that, and all was working fine.

I do have a followup question though. The wiring (buried in the car) had a 300mA fuse wired in line on constant, and a 3A fuse on accessory. I replaced the 300mA with a 1A (had it lying around) and it worked for about 10-15 minutes with no problems, but one of them popped (I haven't pulled it all out to see which one yet).

Do you guys have any suggestions for what to use as far as fuse size? The Pioneer HU has a 10A next to the connector, and I believe my factory fuse box has a 6A ceramic fuse (old school style).

I'm not running anything crazy at all. Literally, the headunit, stock front speakers, no rear speakers, no amp, no sub. The HU has USB (that I plan to use often) and possibly a 3.5mm aux.

TIA!