Mounting of Inverter..

[titanite]

Hello,
I have a 2007 classic duramax. I want to add an inverter incase I need power for something (blender, saw, or whatever). I ordered a unit that is 11.61 x 10.24 x 3.46 in size. I dont really want to run cables all the way to the back seat from the batteries, and there is not really any open space under the hood. Has anyone come up with any good ideas of where to mount either under the hood or some where else to keep the cables short??
Thanks in advance..
T

[DmaxMaverick]

If you figure a way to get it in w/o cabling, let us know. Cables can be a PITA, and depending on the output rating of your inverter, can get quite large. A cigarette lighter socket (or 12V power outlet) limits it to about 200w AC output, which isn't much power, and won't run most blenders or saws. Location is everything. Underhood is absolutely out of the question, even if there is room. Heat will kill the inverter, and inverters that aren't designed to operated under high temps will die young if adequate cooling isn't provided. You can get high temp inverters, but they are many times more $$ than the standards.

If you want an onboard installed inverter, choose a location where it can get good ventiliation, isn't too hot (under any conditions when it may be used), and can be wired properly. The length of the cabling is important, too. 12V impedence is much higher than 120V AC, so the longer you run it, the larger the wires need to be. Measure it and calculate the input requirement before you settle on a wire size. You only need to run one long leg (batt+), as a chassis/frame ground will work fine. Don't look for an underdash power source, as there are none that will support the power demands w/o causing problems with the electrical system.

If you don't want to run wires, the only option is to keep it portable. Either with gator clamps or a connector off the batteries.

[titanite]

Thanks for the input. Its a 1500W continuous. Any ideas how to safely get the positive wire (thinking 0 AWG) through the fire wall to under the back seat? Cant think of any other place to put it...

[DmaxMaverick]

There are several options for getting the power through the firewall. You can parallel and existing harness passthrough, pierce a grommet/plug (there are a couple) or make a new hole. Getting the power to the rear is easy. There is a chanel under the rocker trim that will accomodate a large harness or cable, and runs the length of the cab. You can see it (in part) if you go to the "truck stuff pics" link in my sig. It is in the misc. album, and was originally put up for a frame mounted compressor harness install (for airbag onboard compressor). The picture is of the rocker panel just below the driver side seat. There is also one on the other side, so you can use either. 0 AWG is more than adequate for that length, but I think 2 AWG would be fine for 1500W at that length. It's best to measure and calculate. Power can be tapped right off the 12V lug under the red cover for jump starting (way too easy).

[NutNbutGMC]

You mentioned the jump start junction lug. May one hot-fix onto that lug or does one need to disconnect the batteries when connecting to the lug as a power source?

[rsbrx]

I mounted mine on the back wall behind the rear seat using a couple of aluminum brackets I built to keep it off of the carpet about a 1/4" for air circulation. I ran the cable from the jump start lug (+) and a bolt on the block (-) to a set of 4 relay switches. Two wired in parallel per side mounted on the fire wall (engine side). I mounted a small switch in side the cab to turn it on and off. The cable runs down the fire wall to the frame and then under the truck in a loom to a hole I drilled in the bottom of the cab just bellow the inverter. It was a bit of work but I am glad I did it this way as it clean, out of site and easy to use when needed.

[DmaxMaverick]

You mentioned the jump start junction lug. May one hot-fix onto that lug or does one need to disconnect the batteries when connecting to the lug as a power source?

Yes. You can "hot-fix" it with batt's connected. The cable is continuous, in/out, and has an eyelet crimped onto it (it's the left side batt+ cable). The lug is just a common connection point, and does nothing in and of itself. I have about 4 accessory taps on mine and never had to disconnect for the hookup.

[Inspector]

RSBRX:
What relays did you use? Size and part number
Denny

[NutNbutGMC]

Yes. You can "hot-fix" it with batt's connected. The cable is continuous, in/out, and has an eyelet crimped onto it (it's the left side batt+ cable). The lug is just a common connection point, and does nothing in and of itself. I have about 4 accessory taps on mine and never had to disconnect for the hookup.
:tiphat:

Thank you.

[rsbrx]

Denny, sorry for the delay in getting back to you. I had some computer problems I had to get fixed. I used an # 9.0 stranded wire. If I did the math correctly, its sufficient for my inverter including voltage drop for the length of wire and then some. Some one here may be better qualified than I am to say if the wire is big enough or not. I used 2 relays per side for a total of 4. Two wired in parallel on the positive side and two wired in parallel on the negative side. I also paid close attention to wire lengths in the parallel parts of the circuit and soldered all the connections. This was to avoid as much resistance differences as possible. (So that on side of the parallel path would not be any easier to travel than the other.) I also do not switch the relays on with a load. I apply the load after the relays are closed. The relays I used are Bosh 12 v 20/30 A and the part number on top of the relay is 0 332 209 150. Its been a while since I built the system. I had it in my 05 prior to the 07. I currently don

[rsbrx]

I posted a few inverter install pictures under my user profile if you want to check them out. I was going to post a link here but when I went to the photo album page all I got was a blank page. Maybe its part of yesterdays update?

[NutNbutGMC]

I posted a few inverter install pictures under my user profile if you want to check them out. I was going to post a link here but when I went to the photo album page all I got was a blank page. Maybe its part of yesterdays update?True that. I think they have reupped the pics.