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.
Plus the 6 foot power cable for my 1998 F150 with the 4.2
Looks like 6 feet will be good enough, as there is a hole in the firewall near the steering column with a
plastic plug in it I can drill thru which will probably be ok as a "grommet" more or less for these 2AWG power cables.
Next issue is where to mount the inverter. I have a hamset mounted on the bottom of the dash in the center so not much room there.
The transmission "hump" seems to have a flat surace that would work...I thought maybe Velcro but perhaps short 3/4 inch sheet metal screws
would be ok? I am not sure how much clearance I have there to drill thru, or is it a bad idea to drill there at all?
Depending on how much power you try taking from the Inverter, 1000 watts is 120vac X about 8 amps = 960 watts at its max specifi8ed limit.
On the 12 volt input end it, will be 12vdc X 80 amps plus for inverter efficiency to output 960 watts plus the wiring for 100 amp capacity and fuse protection.
Then you would need the engine running at somewhat higher Idle for the Alternator to supply the necessary current and keep the voltage up.
Battery and Alternator needs to be in good condition.
Good luck.
Ive kept small inverters in a few vehicles but never installed them permanently.... Usually just plug into the lighter socket when needed. Works okay for things like TV / VCR for small kids on long trips to see lots of movies...... Multiple cell phone chargers, etc. for anything big you need to use the clips and clip it to the battery directly... Big wires... And theres still not that much you can operate with them.... Unless you're just bringing small appliances camping.. like a coffee maker ... You can forget running any sizeable tools.... And most tools are cordless today.... Might work for charging cordless tool batteries..... Or auxiliary lighting
But for any of these things I can't see wanting to install one permanently
I wound up making a bracket for the inverter from scrap wood, came out ok. Used industrial strength Velcro to
mount it to the cab floor mat. I connected power to it yesterday morning. I fed the + side right
on the stud marked with the arrow.
That stud is always hot, could not find a spot that the 2ga wire
could get on that has switched power for when the eng is on
and off when its off.
Went on a drive yesterday and the batt died in the parking lot.
I felt the back of the inverter and it was kind of warm, so the thing
draws standby power even when the front switch is off I guess.
I disconnected the red wire from it, and a guy in the parking lot
said he would help. He had one of those slim portable batteries that
are suppose to help borderline batteries get started. We tried a few times
with it, but it didn't turn over the engine completely and after a few more tries, it
still didn't help.
Someone else came over with a Jeep SUV and we used my cables to his vehicles
battery.
It turned over a little better but still not enough. We let it charge a few
minutes, but still same result.
He noticed the brand name of the battery in there as a Walmart brand and he
said his friends get raw deals with them all the time. He said the sticker on mine has a date
code of 8-24 which is exactly 1 yr which is the length they cover the battery for under warranty, so
returning it for an exchange was probably not possible.
Luckily, there was an Advanced Auto parts store in walking distance so I
went there and they supplied a Sears Die hard for a whopping $230, core charge included. Apparently they
bought the Sears Die Hard brand a while back.
Lugged that thing back to the vehicle, luckily I carry my tool box now all
the time, and swapped batteries and it started up on the first turn. Handed them back the Wallymart batt for the
core and I am back in business.
So I will have to figure out where to connect the red wire so that its not
got hot power all the time. I wonder if any of the locations nearby on that junction box will work....
Someone said probably buy a 100A/12V relay contactor and use it to power the positive cable and
activate the relay with 12V from a feed somewhere that has 12V only when the eng is on.
Live 12V feed
Inverter bracket
Last edited by Teknoskillz; Aug 24, 2025 at 10:58 AM.
Reason: typo
So I bought a 12V relay rated at 50A which is more than the inverter demand will be for what I will use from it. Mounted it
above the engine on part of the firewall thats clear.
Trick now is finding a spot in the fusebox in the eng compartment thats Hot when in Accessory and ignition.
Anyone know of a resource online showing the connections available?
It is poor circuit design policy to switch very high currents anywhere except to the Starter motor on any regular basis.
Even this is done by slave operation relay.
The old type starter relays are slave relays and fail after a lot ot use..
The high current contacts burn mostly from the Starter Motor Inductive kick back voltage..
To produce 400 watts at 120 volts and 3.5 amps threw an Inverter costs about 30 + amps out of the Battery, Inverter losses and the heavy Leads required on the 12 volt side.
Ignition on power for this application full time is not a good expectation.
Need to only turn on when Inverter is needed.
Stock system operates that way and with fault control.
Good luck.
The inverter has a power button on the front , however it will draw some small current for standby power with that button off,
but its likely way under 1 amp, so the startup drain on the battery will be minimal. Unless I forget and leave something plugged into
the inverter which draws high power, but the idea is to make sure the engine is running when using the inverter. The connections
in back of the inverter are also going to my 2 meter ham radio mobile which can draw like 20 amps when transmitting so the inverter
input terminals come in handy as they are close by the ham radio.
Originally Posted by Bluegrass
It is poor circuit design policy to switch very high currents anywhere except to the Starter motor on any regular basis.
Even this is done by slave operation relay.
The old type starter relays are slave relays and fail after a lot ot use..
The high current contacts burn mostly from the Starter Motor Inductive kick back voltage..
To produce 400 watts at 120 volts and 3.5 amps threw an Inverter costs about 30 + amps out of the Battery, Inverter losses and the heavy Leads required on the 12 volt side.
Ignition on power for this application full time is not a good expectation.
Need to only turn on when Inverter is needed.
Stock system operates that way and with fault control.
Good luck.
Was thinking of Loc 6 in the eng compartment fusebox , says its for:
"Radio, Premium Sound Amplifier, CD Changer"
I yanked the fuse but it read hot 12V both sides of the terminals inside the box where
it was plugged into so I dont think that will work. I need something thats hot with the ACC or the ignition on.
The cabin fusebox says pos 8 is for the radio, rated at 5A, so may try that.
Unless there is another easier spot to tap into under the dash?
Mounting a power inverter
