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Where to get switched 12VDC on 04 chevy express 3500?
Where to get switched 12VDC on 04 chevy express 3500?
I want to connect a battery isolator inside engine area so I need switched 12VDC.plan to ground at firewall.
I believe fuse #29 in engine areas fuse block is a output for auxiliary.
What is the easiest way to get switched 12VDC? The engine fuse block is kindof tight
To be connecting upto. I know theres a 2nd FB under driver seat I read there a 3rd
Auxiliary FB behind the glove box. My van only has a doghouse no glove box so I must have misread here https://www.autogenius.info/chevrolet-express-2003-2007.../
I was considering tapping the main FB in engine area 29 circuit w/ a tap.
I'm considering the stinger relay type isolator however I'm concerned w/ how much power it will consume.I want start battery an house battery separated so house battery won't suck the start battery down.
Thanks for advice
Last edited by the Brain; January 14th, 2023 at 2:33 PM.
the set up you describe is already in use on the roadtrek-modified express 3500 chassis. The roadtrek modification uses an isolator which is installed at top of firewall under the hood . the cutoff for house battery power on/off inside the van is by 2 rocker switches on the roadtrek control panel by the side door ( which also has the generator start/stop and house battery on/off to power refrigerator, propane heater, and stove starting current , and powers fluid tank level sensors. ) the diagrams on the wiring of the isolator for the house battery are not available from chevy but are on the roadtrek io soup, a free group on yahoo for 3500 s with the roadtrek modifications. ( in fact the chevy dealer where I took my 3500 to investigate no charging of my house battery misdiagnosed the problem as a bad alternator, when it was merely a $100 new isolator it needed. ) if you pm me I can look through my paperwork on the isolator wiring on my oem roadtrek 05 and 07 3500 chevy express vans (which were support vans fo my work as an EMT. ) Roadtrek kindly sent me a wiring diagram of their OEM isolator setup.
the set up you describe is already in use on the roadtrek-modified express 3500 chassis. The roadtrek modification uses an isolator which is installed at top of firewall under the hood yes my Pleasurway Lexor is very simiarl to the roadtrek, yes I have the sure power 160amp 2 battery isolator. the cutoff for house battery power on/off inside the van is by 2 rocker switches on the roadtrek control panel by the side door ( which also has the generator start/stop and house battery on/off to power refrigerator, propane heater, and stove starting current , and powers fluid tank level sensors. )my van has a house battery kill switch located in rear of van I turn it on when I want house 12VDC and to allow the chevy alternator to charge both batterys the diagrams on the wiring of the isolator for the house battery are not available from chevy but are on the roadtrek io soup, a free group on yahoo for 3500 s with the roadtrek modifications. ( in fact the chevy dealer where I took my 3500 to investigate no charging of my house battery misdiagnosed the problem as a bad alternator, when it was merely a $100 new isolator it needed. ) if you pm me I can look through my paperwork on the isolator wiring on my oem roadtrek 05 and 07 3500 chevy express vans (which were support vans fo my work as an EMT. ) Roadtrek kindly sent me a wiring diagram of their OEM isolator setup.
yes I PM you for the RT wiring diagram doc.
what happened on my inaugural 1st night in van I accident left the red key (battery kill switch) on for over 12 hours which turns on the cabon monixde and propane sensors they draw .5 amps very little power that the house battery should of handled even longer than 12 hours.additionalley I believe the refer (which is not being used as of now) was turned on it's switchs certainly wheren't pointed to off.
the isolator is designed to allow current to flow from house battery & block current flow from start battery, basicelly protecting the start battery from being drained.
during this 12 hour period the opposite happened the isolator didn't block current flow from start battery and the 2 sensors drained the start battery down to 8.5VDC this battery has been recharged an is fine.
I inspected the wiring at isolator an found that post 1 which is for start battery was unconnected. after testing isolator post 1 is faulty.
thats proballey why is was unconnected!
I found a thick 0awg wire out of Alternator to post A & a thin organe 16awg (I thought this was the alternators excite wire nowadays referred to as a sense wire) wire to post E (E mite be switched 12VDC yet to check this,not sure what E even is?)
post 2 is house battery.
I've tested the isolator post 1 is faulty I believe I get a replacement isolator connect the already wired posts then add a 0awg wire out of post 1 directly to positive of start battery.
Mitch so you are a EMT do these abulances has extra powerfull alternators or even more than one alt.? I'm surprized that pleasureway has a 105amp alt. when tahoes have 145amp alts. seams kindof weak to have a 105 amp.
thanks so much for isolator wiring advice
Originally Posted by mountainmanjoe
Don't use isolators. Use a dedicated battery DC-DC charge controller.
Dual battery systems are described in the electrical manuals on gmupfitter.com
I will check gmupfitter. I may not have a choice to not use isolators. thanks
Last edited by the Brain; January 16th, 2023 at 10:43 AM.
update the small 16awg organe wire is a switched 12VDC when key is on theres 12VDC
so the isolator must be powered to direct the current properly.
what I am now confused on is the GM wiring to starter selinoid that needs to be dissconnected? I've read there should only one path from the isolator to starter.I read that the alternator is daisy chained to the starter silaniod and needs to be disconnected.
Last edited by the Brain; January 16th, 2023 at 7:20 PM.
January 14th, 2023, 2:31 PM
Where to get switched 12VDC on 04 chevy express 3500?
