# Lack of power **URL:** \ **Category:** SON240sx Automotive\ **Created:** [August 28, 2006, 11:23pm UTC](https://forums.speedlife.net/t/lack-of-power/99398 "2006-08-28T23:23:28Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Mista\_Sparkoh](https://avatars.discourse-cdn.com/v4/letter/m/3bc359/32.png) [@Mista\_Sparkoh](https://forums.speedlife.net/u/Mista_Sparkoh)\ **Post date:** [August 28, 2006, 11:23pm UTC](https://forums.speedlife.net/t/lack-of-power/99398/1 "2006-08-28T23:23:28Z")
I jus got my headunit, amp and speakers professionally installed. It wasn’t until today that I finally got a chance to take my car for a spin and I noticed something wierd. When my tach needle drops below idle, the amp cuts off and no sound comes out of the speakers. With my manual e-fan switch on, the amp cuts off as well (only when I’m idling). And also, when I turn the key to ACC, the headunit lights up but no sound. Does it sound like the alternator? Another question I have is about the rpms dropping. I mentioned it in a previous thread but with no luck. So I guess I’ll ask again. When I’m cruising and do a hard stop, the tach needle drops rapidly. Sometimes low enough to cause the car to stall. ANyone know what the cause is? ---
**Author:** ![snowboard\_240sx](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/snowboard_240sx/32/5519_2.png) [@snowboard\_240sx](https://forums.speedlife.net/u/snowboard_240sx)\ **Post date:** [August 29, 2006, 3:50am UTC](https://forums.speedlife.net/t/lack-of-power/99398/2 "2006-08-29T03:50:09Z")
well the reason ur amp dies out, i would think is because u need a new alternator…now as for the “idle dipping disease” u experience, it can be many things, vacum leak, ive heard that u can take electrical cleaner from radio shack and use it on every plug in ur harness. Its like some cleaner for electrical parts unsure of what its called…or a bad ground? try everything ---
**Author:** ![Mista\_Sparkoh](https://avatars.discourse-cdn.com/v4/letter/m/3bc359/32.png) [@Mista\_Sparkoh](https://forums.speedlife.net/u/Mista_Sparkoh)\ **Post date:** [August 29, 2006, 10:59am UTC](https://forums.speedlife.net/t/lack-of-power/99398/3 "2006-08-29T10:59:20Z")
where would be the most likely place that would result to this problem? snowboard, thanks for the suggestion. I’m confused cause I dunno where I should start. The wiring under the hood is all messed and it’s hard if not impossible for me to check all the vacuum lines. Anybody else have had similar symptoms? ---
**Author:** ![DarkForceJackal](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@DarkForceJackal](https://forums.speedlife.net/u/DarkForceJackal)\ **Post date:** [August 29, 2006, 12:01pm UTC](https://forums.speedlife.net/t/lack-of-power/99398/4 "2006-08-29T12:01:33Z")
Start with checking and cleaning visible body grounds (usually wires ending in a washer-style connecter, screwed into the body or engine block, approx 6-8 or so under hood I believe), and then have your alternator tested to ensure it’s producing the correct voltage. It does sound like something with your wiring could be a problem…so in the end you may have to track a possible problem there down or head back to the shop where you had your stuff installed. Perhaps your manual e-fan switch or amp is hooked directly to the battery instead of a good ignition source and that causes a problem? I’m no wiring pro though… Good luck. ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [August 29, 2006, 12:07pm UTC](https://forums.speedlife.net/t/lack-of-power/99398/5 "2006-08-29T12:07:12Z")
start your car and test the voltage with a multimeter and then that will tell you if its time for a new alternator and then replace it (not that hard of a job) and go from there ---
**Author:** ![Mista\_Sparkoh](https://avatars.discourse-cdn.com/v4/letter/m/3bc359/32.png) [@Mista\_Sparkoh](https://forums.speedlife.net/u/Mista_Sparkoh)\ **Post date:** [August 30, 2006, 12:02pm UTC](https://forums.speedlife.net/t/lack-of-power/99398/6 "2006-08-30T12:02:19Z")
thanks alot. THe problem is that I didn’t do the engine swap and it wasn’t done by a shop. I bought it with the engine installed already. So you can see why I’m having difficulty locating various wirings and grounds. If I did myself, I wouldn’t be so dumb-founded. But thanks for all the suggestions ---
**Author:** ![rix240sx](https://avatars.discourse-cdn.com/v4/letter/r/e56c9b/32.png) [@rix240sx](https://forums.speedlife.net/u/rix240sx)\ **Post date:** [September 1, 2006, 1:58pm UTC](https://forums.speedlife.net/t/lack-of-power/99398/7 "2006-09-01T13:58:35Z")
if u tighten the bolt on your alternator half or a full turn u can prolly stop or help it because the belts probably old too u might want to get a new one even thats up too u. try tightening it first u will have to take off ure intake tubing then go infront of the tension bolt i guess u can call it and theres a little bolt u gotta crack (loosen) b4 u tighten up the other one hope it helps