Need Help with Voltage Drops

Anonymous
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I have 2 Viper 1200's and a Viper 200.4 and when i am sitting at idle and bumping my system at full volume my battery light comes and the voltage drops to 10-10.5. I have a stock 136 amp alt and an upgrading 1100 amp RF battery however i only have a 150 amp circuit breaker under the hood and i have not had the big 3 done yet. The problem is that when ever i am playing it the battery light comes on and then it will shut down. So will upgrading my circuit breaker to 200-250 and getting the big 3 done solve the problem to where my battery light will not come on and shut down my system. If that won't do it what other options do i have because it is a 2004 Durango and i brought it to the local alt shop and they said they could not upgrade the new dodge alts. So if anyone has any other suggestions to help with this or if you know where to get a HO alt for the new Dodge's let me know.

 
What size power wire are you running from your battery to your amps?

With that much power.. let me tell you what you should be doing.

Minimum of one run of 1/0awg to the two 1200D's. Use a 200-350A fuse under the hood (ditch the circuit breaker). Split it with a distro in the back by the amps to two 4awg runs, each fused at 150A. For your smaller amp. You can either split off of the main 1/0awg run (not recommended) or run a seperate auxilary run from the battery to the back specifically for that amp. Fuse under the hood at 150A (for 4awg) or 80 (for 8awg).

Do your big three as soon as possible and make sure you do it in all 1/0awg. Clean your grounds front and rear and ensure tight connections.

After you do all of that, then start looking for a high output alternator if you still have problems.

 
Well the D1200 seems to be over rated it has two 30A fuses (14.4V x 60A = 864W @ 100% eff) So each model CAN pull 60A total. Thats 120A for the subs and the 200.4 is 25A. 4 Gauge is probably too small - your basically at the max limit of it and 2 gauge would be advised (or bigger) You can run your whole system off one 2 or 1/0 gauge wire with dist blocks in the rear to split power three ways.

I would remove the breaker and replace with 150 or 200A Fuse. I say fuse because breakers are not reliable - anything larger will not make a difference since the max you can draw is 145A.

Upgrade your Big 3 and make sure all connections are tight. If you have access to a battery charger - charge the battery while doing the other work. Retest after work is complete, I think the grounds will make a difference. After completion upgrade if required. 136A factory unit is pretty good in size, I am sure it can be made stronger if you do need it though

 
Get a bigger fuse. I have a 350 under my hood for my Orion 2500. Do the BIG 3 and/or get a bigger alternator...check your other thread out, I left you a link.
The Orion 2500 is a beast compared to the Viper 1200. DEI recommends dual 4 gauge to it and a 250A Fuse. A little math show what 250A will bring power wise compared to the Viper model (14.4V X 250A = 3600W @ 100% eff)

No amp is 100% efficient so we have to multiply this by .75 to assume 75% efficiency (a little more realistic) That nets you 2700W three times the 1200's output @ 100% efficiency - which again does not exist.

 
whoops - was looking at the Directed model not the "Viper" model - so a 200A fuse would suffice and 2 gauge or 1/0 would be fine. 1/0 can safely handle 300A+ so you can still run one cable for the entire system

 
So i should get rid of the circuit breaker and replace it with a 300A fuse and check my grounds and get the big three done? Will that stop my battery light from coming on and shutting down my system? Because i had this same setup sealed and i had no problems then i went ported and now my battery light comes on and the circuit breaker shuts the system down. Will the fuse go in the same place as the circuit breaker? Do i need to upgrade my circuit breaker too or just get rid of it and do i need a separate fuse for my 200.4 if so what size. I also have a 1 farad cap should i upgrade that? Does anyone have around the same setup if so tell what you use to keep voltage up because i really don't think i need an alt because it did fine in the sealed box. Do you think the grounds could be grounding wrong because it was fine when i got it from one shop then i took it to another shop to have the ported box built and it has not been right since. Pretty much i am asking if upgrading my fuse and wires and securing the grounds will give me enough voltage?

 
As stated - remove the breaker - a 200A - 250A fuse is all you need, larger will not do any better (wont hurt - but its there to protect the circuit and max capacity is 205A of your amps)

The voltage problem is in connections, you probably have a bad one but if you never upgraded the ground from battery to chassis - that needs to be done as you are relying on a factory 8 gauge wire most likey to ground a 205A added draw to your charging system. You can run the entire system off one 1/0 or 2 gauge wire run and the block would need to hold three fuses two at 90-100A and the other at 25-30A. Wire it correctly recheck grounds - you should not have a problem after.

 
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