Circuit Separation

DesertGuy · Post by **DesertGuy** » Sat Apr 21, 2007 1:07 pm

Looking at which circuits are activated by which fuse panel... Does this look correct or is there a better way?

BATTERY FUSE PANEL

Ignition/Start Circuit
Horn
Hazard
Computer Harness (Battery Feed)
Dome Light
Radio Memory
Headlights
Running Lights
Brake Switch (Optional)
Whip Lighting

IGNITION FUSE PANEL

Off-Road Lights
Gauge/Dash Lighting
Turn Signals
Brake Switch
Alternator Idiot Light
Oil Idiot Light
Computer Harness (Start Circuit)
Fuel Pump (Relay Triggered)
Radiator Fans (Relay Triggered)
CB (Optional)

ACCESSORY FUSE PANEL

Radio
Intercoms
GPS
DVD Player

Speedy Jim · Post by **Speedy Jim** » Sat Apr 21, 2007 3:12 pm

Move Fuel Pump to "Ignition".

(Assume the pump would also have some kind of safety circuit
to prevent running after engine stall, such as after an accident.
Or, an inertia switch.)

Post by **2088 bob** » Sat Apr 21, 2007 4:53 pm

ignition and accessory controlled is pretty much same thing

DesertGuy · Post by **DesertGuy** » Sat Apr 21, 2007 4:57 pm

2088 bob wrote:ignition and accessory controlled is pretty much same thing

Does that stand true for a BATT/START/IGN/ACC ignition switch? If they are indeed the same, why wouldn't I just have a jumper between IGN/ACC?

This type of switch

Post by **2088 bob** » Sun Apr 22, 2007 2:59 am

check for continuity between batt to ign and batt to acc

Ol'fogasaurus · Post by **Ol'fogasaurus** » Sun Apr 22, 2007 7:58 am

I keep the mast (whip) light on the un-switched side. We have been known to sit out on the dunes with the mast light on so we can be seen. That way, there is less load on the battery when all else is off.

If you have a CB, I now switch it. A lot of people leave it on the hot side, but when they come back into camp and get refreshments and forget the CB the whole camp is wake listening to the chatter.

I also leave the brake light on the hot side. That way you have brake lights at night when you are sitting. Someone comes flying out of the night, hit your brakes and they can see you.

Radiater fans. Hmm! Do you have a run-on circuit or a temp senser? Maybe that is another cantidate for a hot side hook-up.

GPS??? If you make new settings or planning a course, should it be hooked to the Hot lead too?

My two-bits worth. Lee

Post by **Marc** » Sun Apr 22, 2007 8:22 am

Ol'fogasaurus wrote:...I also leave the brake light on the hot side. That way you have brake lights at night when you are sitting. Someone comes flying out of the night, hit your brakes and they can see you...

Makes sense to me. For that matter, why wouldn't you want running lights and headlights to be functional with the key off too?

Ignition and Accessory positions are NOT identical, they use independent contacts. Everything on the ACC terminal is powered with the key in either position, but those loads on the IGN terminal are only hot when the key is ON. Keep in mind just how much current you're piling onto these contacts - the designers probably weren't expecting much more than 20-25A total in current draw for either set. If you must run big loads controlled by the key, a load-reduction relay (or two) may be in order.

DesertGuy · Post by **DesertGuy** » Sun Apr 22, 2007 1:03 pm

Sorry for being thick-headed, but I must be missing something. Below is the Ignition Switch that I will be using (same as above pic). The ignition switch has four wires; Red=Power, Brown=Accessory, Pink=Run, Purple=Start.

When the key is turned to "Run", continuity is between the Red, Brown, and Pink wire. When the key is turned back to "Accessory", there is only continuity between the Red and Brown wire... no longer the Pink. Finally, when the key is turned to "Start", continuity is only between the Red, Pink, and Purple... continuity does not re-establish to the Brown wire until back to "Run"

That being said, I was planning on using a 15amp fused circuit to run through the ignition switch and have the respective wires "trigger" their high amp relay to provide power to those particular circuits on the fuse panel.

If I run items like the radio and such off of ACC, then when the car is stopped I can listen to the radio without hearing the fuel pump cycle.

I thought I was thinking along the correct lines; however, after reading the posts above, I am not so sure...

rickosuave1987 · Post by **rickosuave1987** » Sun Apr 22, 2007 10:59 pm

I understand what youre saying about the radio, and I completely agree. That is how newer cars are wired so you can just have "accessories" on, like the radio and GPS and such and not end up busting your fuel pump. That is also why radios usually turn off when you start your car.

One thing Im not too sure about is your headlights. I understand that it would be the safest bet to have them turn off when you take the key out, but what if you need some quick light at camp? I like the ease of not having to fumble around for the key, rather just reach in and flip the switch.

DesertGuy · Post by **DesertGuy** » Sun Apr 22, 2007 11:31 pm

Thanks for the input so far... updated list

Ol'fogasaurus · Post by **Ol'fogasaurus** » Mon Apr 23, 2007 7:47 am

Heck of a thread! I am workng the same question myself.

Rick, got a question on your last post.

What about only running a single light, or a single two set of lights hot. Have you have ever been in camp, late at night, trying to sleep and someone or several vehicles come in with 6 lights burning so hot you could fry eggs at thirty feet with them. If you reduced the lights that can be used with the engine off to one or a two light set might be a friend friendly way to do it.

Just thinking out loud.

Actually this has happened to us. It was also before the limits to the hours you could drive were installed on the (Oregon) dunes.

rickosuave1987 · Post by **rickosuave1987** » Mon Apr 23, 2007 3:22 pm

Ol'fogasaurus wrote: Rick, got a question on your last post. What about only running a single light, or a single two set of lights hot. Have you have ever been in camp, late at night, trying to sleep and someone or several vehicles come in with 6 lights burning so hot you could fry eggs at thirty feet with them. If you reduced the lights that can be used with the engine off to one or a two light set might be a friend friendly way to do it. Just thinking out loud.

I agree, I wasnt meaning that ALL the lights had to be on at the same time. I was just saying its nice to not have to turn the key to get one or 2 of them on.
If I need a little light in camp, I have an off road light on the rear bumper of my baja and flip that on so its not 6 100w lights that make it feel like day, rather just 1 55w mellow light.

Post by **2088 bob** » Thu Apr 26, 2007 2:07 am

Steve sorry to be misleading the last cheap ignition switch i used didn't have an acc pin allthough the the key did have a acc position most of the last few rails and fiberglass car we have done did not use ignition keys but rather a progressive toggle and a relay that pulls up in the run position

MNAirHead · Post by **MNAirHead** » Thu Apr 26, 2007 5:49 pm

I've found several higher quality without Acc settings.

Is there a way to tell the difference between cheap and good?