When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey guys, I'm wiring an amp into my C4 for my sound system. I want to tap a wire from the positive terminal of the battery to the amp, but I'm stuck with those stupid side mount connectors for the battery.
Image above is the same style of connectors. I have no idea how I'm supposed to 'properly' wire my amp to this. Lots of other batteries have a few terminal posts which you can put all kinds of stuff onto. With this I don't see any way to do it.
Does anybody know of a solution that doesn't involve buying a different battery? Thanks!
You want a positive cable connection, you have the rest figured out?
If that's all, there's a lug below the battery tray where all the fusible links mount and could take another ringlet connector on most times. It should be electrically hot all the time.
Much depends on how your positive cable is fabricated now. There are many different S/T adapters that are used to add accessories using the S/T battery. If you're already stumped and insist on mentioning 'stupid' etc maybe you need to consider a 'for hire' install.
I believe you have an '85 so you can avoid looking for the jump-block mentioned in post#2. There's very inexpensive adapters that you only remove the S/T bolt from the cable end and use the adapter. The adapter has correct threads for the S/T depth and a male threaded stud for cable attachment using ring terminals.
Like anything else there's likely good/better/best.
Much depends on how your positive cable is fabricated now. There are many different S/T adapters that are used to add accessories using the S/T battery. If you're already stumped and insist on mentioning 'stupid' etc maybe you need to consider a 'for hire' install.
I believe you have an '85 so you can avoid looking for the jump-block mentioned in post#2. There's very inexpensive adapters that you only remove the S/T bolt from the cable end and use the adapter. The adapter has correct threads for the S/T depth and a male threaded stud for cable attachment using ring terminals.
Like anything else there's likely good/better/best.
Perfect, that sounds like just what I need! I knew something had to exist, but I just wasn't even sure what to search for. Also yes, I do have an 85, so I'm sure there are a few differences between the new style wiring and mine. Thanks guys!
I haven't considered that, is there a reason why I should consider it over the battery terminal?
I found an adapter plug like the one mentioned above today at an audio shop, so I'll give that a shot and see if it will work for me.
For context, I'm using a smaller amp so I can hide everything inside the dash under the head unit. It's a tight fit, but after test fitting I have confirmed that it will work. Advantage is that I don't have to run cables all over the car, and if you were to sit in the car without me saying anything there's no indication that the system isn't OEM. Head unit is a Retrosound, so if somebody were very keen to the look of the OEM C4 head units then I suppose that's the only tip-off. Speakers are upgraded, but the grills remain OEM.
Anyway, unless there's a shorter/easier way to go from head unit area to a good positive power source, I think this is my best option (run directly from amp, along kick panel, through the firewall, tapped into battery).
Any other ideas are welcomed, but I can do without the sass
The amp has power in, ground out, and an ignition input. Doesn't that mean it only turns on when the ignition relay is switched?
Basically - that is correct. But the Amp does consume a very small amount of power while just sitting there Will it discharge the battery overnight - NO - but will it add to the parasitic draw that the battery gets to deal with - YES ... So - bottom line - if you don't drive the car for extended periods of time - you might want to think about a maintenance charger - like a Battery Tender or an C Tek.
Two other "friendly suggestions". 1) Use a healthy grommet when you run the power wire through the metal / plastic into the passenger compartment. (You might want to consider putting a fuse on the power wire to the amp - just in case).
2) Car stereo power amps tend to get rather "warm" in use. They really "like" some airflow around them to keep them cool. The location you picked does not seem to offer much potential for airflow - so you might want to check the temp of the amp with an IR temp "gun" after cranking the system for 10 - 15 min. Sometimes the manual will have a max "safe" temp - but I'd check with the mfgr to see what they consider to be "safe". And remember - it's Jan now - if the car interior is 120 degrees (which is frighteningly easy on a 90 degree day) - the amp is going to be starting out at that temp as well - so getting to the point where transistors turn into crispy critters isn't that much of a stretch...
Last edited by Purple92; 01-17-2018 at 06:25 PM.
Reason: correcting typo
if you don't drive the car for extended periods of time - you might want to think about a maintenance charger - like a Battery Tender or an C Tek.
I intend to daily the car, so it shouldn't be a problem.
Originally Posted by Purple92
1) Use a healthy grommet when you run the power wire through the metal / plastic into the passenger compartment. (You might want to consider putting a fuse on the power wire to the amp - just in case).
I have a fuse in-line from the power lead already, but thanks.
Originally Posted by Purple92
2) Car stereo power amps tend to get rather "warm" in use. They really "like" some airflow around them to keep them cool. The location you picked does not seem to offer much potential for airflow - so you might want to check the temp of the amp with an IR temp "gun" after cranking the system for 10 - 15 min. Sometimes the manual will have a max "safe" temp - but I'd check with the mfgr to see what they consider to be "safe". And remember - it's Jan now - if the car interior is 120 degrees (which is frighteningly easy on a 90 degree day) - the amp is going to be starting out at that temp as well - so getting to the point where transistors turn into crispy critters isn't that much of a stretch...
The amp has a built in fan, so I'm not too worried about it. I'm not exactly going to be maxing the thing out anyway. I'm not running a sub, nor will I ever.
I appreciate all of the feedback, and I now have my system configured the way I need it. I did a test wiring setup and everything works as intended, but I'm having problems with front right and rear left speakers not working... They worked before when I had them just wired to the head unit, so I'll have to investigate further. I'll take some pictures and video after work so you all get an idea of what I came up with, and in case somebody else wants to do a similar setup.
Finished everything up and took it for a drive. I have some alternator whine in the signal, but aside from that everything works great. I've read another post that mentions putting the amp ground on the passenger seat bolts, supposedly that solves the problem. I'll try that in the coming weeks and I'll post here whether it worked or not.
Tried grounding to the seat bolt today, it was MUCH worse. Absolutely not the way to go.
My buddy is an electrical engineer, and he's pretty familiar with sound systems. He's thinking maybe grounding the head unit and the amp to the same location will further reduce the signal noise, or if that doesn't work then perhaps an in-line filter from the alternator will reduce the noise.
With my original ground point (aluminum plate behind the head unit) it's certainly not horrible, especially considering how loud my muffler deleted exhaust is, but I think I can make it cleaner. I'll post again if I find a way to make it perfect.
01-16-2018, 03:49 AM
Amp wiring and battery help
