Lack of power

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?

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

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?

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.

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

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

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