1994 saturn sl2 audio build alpine type r

Have a few questions that would love to be answered. First a little about the car electronics: Power Window, Lock, Manual Trunk Big AGM Battery relocated to back with 4 gauge (Not the cheap doodie) to the engine. 6" Long 3" think braided ground cable to chassis. Here is the audio which is already installed. Alpine 4 Preout :( Head Unit. Not sure of model number but is a newer model. Alpine MRX-F65 (110wRMSx4 @ 4 Ohms) 2x Alpine Type-R 6.75 SPR60C Components (4x 110wRMS @4 Ohms) Alpine MRP-F600 300xRMSx2 @ 2 Ohms 2x doodiety Walmart Kickers Rockford Fosgate 2F Cap Stinger 9Wire Cable run from door speaker wires at head unit to rear amp XScorpion 4 Channel RCA Shielded in one cable (1 Cable 4 RCA's on each end) All 4 gauge Oxygen Free Power Wire With good Grounds. Now this will be the new system: Alpine 4 Preout :( Head Unit. Not sure of model number but is a newer model. Alpine MRX-F65 (110wRMSx4 @ 4 Ohms) 2x Alpine Type-R 6.75 SPR60C Components (4x 110wRMS @4 Ohms Alpine MDX-M110 (800wRMSx1 @ 1 Ohm Stable) 2x Alpine Type-R 12" SWR-1242D (4 Ohm DVC) VM Audio SRCAP4.5 Car 4.5 Farad Hybrid Digital Power Capacitor Stinger 9Wire Cable run from door speaker wires at head unit to rear amp XScorpion 4 Channel RCA Shielded in one cable (1 Cable 4 RCA's on each end) 2x Rockford Fosgate RFI-16 RFI16 16 Foot Twisted Pair RCA Cables Couple questions: I don't want to get a new head unit. I know that the MRX-M110 Has a pre-out. So the plan is to keep the head unit on Rear/Rear then run the rear preout to the input on the MRX than go to the rear input channels on the MDX. I'm assuming I won't loose any quality doing this? Right now I have engine noise. It needs to be gone. I read through the big 3. Is all this is adding additional grounds with the OEM's? Cause I already have that 6"x3" Steel braided cable for my Negative to ground. I will add some nice 2x4 gauge for engine to chassis. Which leads me to my next question. I have heard shorter the ground from amp is better. But also Amp straight to battery. Which is better? Should each amp have a different grounding place to keep the shorter ground cables? or will it matter if I ground the capacitor to the same place as the amps? Battery to Chassis will be a different ground junction from amps and cap. Here is what it looks like right now (It's a mess): I want to make it so the back seats can be laid down easily without any worrying about pulling plugs. What is the best way to organize all the wiring. (Clips, gromments, shielding and where can I get it)

Relocated to the back - so no remaining cranker up front? If so, I presume alternator sense wire (if not a single-wire D+ type) has been relocated to the battery +12V terminal? Place your cap up front to prevent dimming and maybe the engine noise. Your system is too small to require a cap for AGM protection (caps usually aren't used for single AGM battery systems under a few kW unless it's a small AGM). Your engine noise may be due to lack of front battery. Usually people retain their standard (wet cell) crankers and add a remote battery if necessary or desired but that requires a battery isolator etc. Short cables direct from battery to the amps. Ideally power ends of the amps facing each other with the battery in between - the resulting hence physical security meaning no fuses to add resistance - but that is modified (and protection added) to suit the installation. Only if the cap can be used as a distribution block might it be used in the rear, but that does depend why the cap is being used.

oldspark wrote: Relocated to the back - so no remaining cranker up front? If so, I presume alternator sense wire (if not a single-wire D+ type) has been relocated to the battery +12V terminal? Place your cap up front to prevent dimming and maybe the engine noise. Your system is too small to require a cap for AGM protection (caps usually aren't used for single AGM battery systems under a few kW unless it's a small AGM). Your engine noise may be due to lack of front battery. Usually people retain their standard (wet cell) crankers and add a remote battery if necessary or desired but that requires a battery isolator etc. Short cables direct from battery to the amps. Ideally power ends of the amps facing each other with the battery in between - the resulting hence physical security meaning no fuses to add resistance - but that is modified (and protection added) to suit the installation. Only if the cap can be used as a distribution block might it be used in the rear, but that does depend why the cap is being used.

Model:     210 GXL Warranty1:     4 to 5 year full replacement Service Life:     Extended Runtime (minutes)2:     210 Sealed VRLA:     Valve regulated lead acid Heat Resistant:     High Hydrogen Emission:     Low Terminals:     Threaded insert 1/4” - 20 UNC Cells Per Unit:     6 Voltage Per Unit:     12.8 Conductance Value:     1175 Max. Discharge Current (A):     900 Short Circuit Current (A):     2800 10 Second Volts @ 100A:     11.4 Ohms Impedance 60Hz:     0.0050 Capacity at 20hrs: (to 1.75VPC)     106Ah BCI Group Size:     31 Weight (lb/kg):     72/32.7 Height w/ Terminals (in/mm):     8.48/215.4 Width (in/mm)3:     13.42/340.9 Depth (in/mm)3:     6.80/172.7 Float Charging Voltage (VDC):     13.5 to 13.8

I guess I can't edit posts, but it was a battery I had lying around. Will this battery be sufficient? Do I need this 4.5F Cap with this battery? I do not have a battery up front. Wish I had a picture but the engine bay is clean and would rather not have a battery under the hood. I did notice that the engine noise did not start till I relocated the battery to the back.

That's not a small AGM and as I said, your system is too small to hurt it. (It's typically >3kW & maybe >2kW that seem to quickly kill common AGMs of ~75AH.) Place the cap up front where the battery should be. PS - BTW: From those specs, during its mere transition from 12.8V to 11.4V at 100A, that battery is the equivalent of a >700F capacitor. (That ignores remaining capacitance under 11.4V; ignores any charge above 12.8V; and assumes my maths is correct.) I mention that to illustrate how pointless a cap is wrt to a battery for adding battery/energy reserve - not that many suggest tham for that. Besides, after that (700 Farad?) discharge, the battery will still crank & start your engine.

The way this saturn is, it all junctures at the starter. Meaning the alternator wire and the main harness wire. Battery went to harness wire. I than relocated the AGM to the rear, and had a 2 gauge wire run from the back to the starter. What is this alternator sense wire?

Also, if I do place the cap in the front, Can I use it as a jump connection if the AGM were to dead? Meaning, I left my lights on and battery goes dead. Instead of jumping the battery through the back seat (The subs are in front of the battery facing the trunk), could I hook jumper cables there to jump the car?

Also, if I do place the cap in the front, Can I use it as a jump connection if the AGM were to dead? Meaning, I left my lights on and battery goes dead. Instead of jumping the battery through the back seat (The subs are in front of the battery facing the trunk), could I hook jumper cables there to jump the car?

From what I can find, your alternator has no battery "Sense" wire. Although it is a 2-wire type, the 2nd wire is IGN +12V to turn on the regulator, hence what I usually call an LI or LIg type (charge-Light & Ign) or D+ & Ig. Generally 2-wire alternators are SL types = Sense and charge-Light, and if they have Ign they are usually 3-wire - aka SIL. The problem with a single-wire alternator - ie, D+ and including your D+ & Ig 2-wire - is that they can only sense the voltage at their output and use for regulation which is usually a max of 14.4V; typically 14.2V - tho some may drop voltage after a while (eg, to a "float" voltage of ~13.3V). So, if there is a 0.5V drop from your alternator to battery, your battery is only getting perhaps 13.7V which is too low for modern batteries (it will suffer worse sulfation & die quicker). But with an S-type, the alternator (regulator!) senses the actual battery +ve terminal so the alternator supplies whatever voltage is required for a (say) 14.2V battery voltage - eg, 14.7V if there is a 0.5V drop. (Many such alternators are limited to a max of (say) 15.5V to prevent blowing car electrics if there is a bad GND or Sense wire.) I suggest S-types when people remote mount their battery, especially if also running big audio from it since there can be significant voltage drop from front to rear.    But otherwise they are superior because alternator to battery voltage drops are irrelevant. Another advantage with S-types is that it's easy to boost voltage by inserting diodes. EG - typical signal or power diodes will increase alternator output by (multiples of) 0.6-0.7V. For smaller increases (~0.3V), Schottky diodes can be used. That may be an advantage for AGMs like yours that specify a charge voltage of 14.8V which is up to 0.6V higher than many alternator voltages. I'll leave that here. I didn't intend to repeat write so much on S-type alternator's, but FYI and to save you searching...

Ah - caffeine! As to your wiring, as it happens, the Saturn provides the best base. You merely have to run a new HEAVY wire from the (heavy) starter +12V terminal to the rear battery +ve terminal (as you have done). [It should probably be heavier than the OEM starter wire due to the extra length to the battery, and physically protected because you do NOT want it to short to chassis anywhere on its long run!] And of course the battery is grounded to chassis in the rear, else a heavy GND run to the front (typically the engine unless a good chassis-engine GND exists or is added) if there is no suitable chassis or grounding point. Some use both - you can never have excessive grounds (except in cases like this! ). Not that your cap needs to have such heavy wiring, but yes, if it is attached to the original battery +12V wire else starter heavy +12V (thru similar gauge wire) it can be used as a Battery Jumper Terminal. The jumper GND can be direct to the engine block etc if that's simpler. I occasionally jumper direct to starter heavy +12V with GND to engine if there is good accessibility (which is bluddy rare these days!!). Because it's the starter that requires the heavy current, the closer or shorter & fatter the cable, the better the jumping.