Jensen 400 - User Manual

Questions and Answers

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andrew82Aug 14, 2025
Why does my Jensen 400 Amplifier not turn on?
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  Mary HarperAug 14, 2025
  Your Jensen Amplifier may not be turning on due to several reasons. It could be due to no power to the +12V terminal, in which case you should check the fuse(s). Alternatively, there might be no power to the REM terminal, so verify the head unit fuse(s) and wiring. Also, check for a blown main fuse at the battery and replace it after identifying the cause of failure. A blown fuse at the amplifier itself could also be the reason; replace the fuse and identify why it failed. Finally, a faulty ground could be the culprit. Re-ground the main power ground to a bare metal chassis.
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Richard JordanAug 17, 2025
What to do if my Jensen 400 blows fuses?
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  rfranklinAug 17, 2025
  If your Jensen Amplifier keeps blowing fuses, it could be that the power wires are connected backwards; reconnect them properly. Alternatively, there might be an internal problem with the amp.
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matthewcarrollAug 20, 2025
Why does my Jensen 400 have distorted sound?
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  David WhiteAug 20, 2025
  Distorted sound from your Jensen Amplifier could be because the input level control is adjusted too high. Try re-adjusting the input level.
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bhallAug 25, 2025
How to fix engine noise/alternator whine in my Jensen 400 Amplifier?
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  Joel TaylorAug 25, 2025
  Engine noise or alternator whine in your Jensen Amplifier can be caused by several factors. It could be due to ground loop(s); use good quality shielded RCA cables. A faulty ground at the amp or head unit could also be the cause; re-ground both to a clean, bare metal chassis. Inductive coupling might be the issue, so re-route RCA and/or speaker wires away from factory harnesses. Finally, the input level on the amp might be set too high; re-adjust the input level.
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jenniferfrostAug 27, 2025
What does it mean when the thermal protection is activated on my Jensen 400 Amplifier?
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  johnchristianAug 27, 2025
  If the thermal protection is activated on your Jensen Amplifier, it might be because the amplifier is driving a 2-ohm load for extended periods. If the amplifier frequently overheats while driving subwoofers, consider installing a fan to keep it cool.
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Dr. Sarah OwensAug 30, 2025
Why is the volume control on my Jensen Amplifier too sensitive?
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  Christopher OnealAug 30, 2025
  If the volume control on your Jensen Amplifier is too sensitive, it's likely because the input level control is adjusted too high. Try re-adjusting the input level.
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staffordsarahSep 3, 2025
What to do if Jensen 400 Amplifier's low impedance protection is activated?
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  Brittany MorseSep 3, 2025
  If the low impedance protection on your Jensen Amplifier is activated, it could be due to several reasons. The amp might be connected to an improper load, so check the speaker connections. The amp might not be able to drive a 1-ohm mono load (2-ohm minimum in mono configuration), so verify that the speakers are connected properly. The speakers might be defective or blown, so check them. Finally, faulty passive crossovers could be the issue, so check the crossovers.
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James AndersonSep 6, 2025
How to troubleshoot poor bass response on Jensen 400?
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  Todd LawrenceSep 6, 2025
  Poor bass response from your Jensen Amplifier can occur if the speakers are out of phase. Check the speaker polarity; reverse the connection to one speaker only if two subwoofers are connected to the amplifier.
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Jamie JacksonSep 9, 2025
What causes short circuit protection to activate on Jensen 400 Amplifier?
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  jonathanbergSep 9, 2025
  If the short circuit protection is activated on your Jensen Amplifier, it may be due to speaker wire(s) shorting to ground; check for faulty wiring. Alternatively, a defective crossover could be the cause.