I've just added a leisure battery, split relay and circuit swap loom to a newly acquired Mazda Bongo. Also added was a 1000W pure sine wave inverter, hooked up directly to the leisure battery. That's in the glove box. There's room above that for the radio body, as far as I can tell.

Rather than feed the radio power cables back through the bulkhead, does anyone know if there are any potential problems with hooking it up in parallel to the inverter, i.e. connecting the + and - to the inverter's terminals?

I'm assuming it'll power just the same, only putting the inverter cables under more work if both on at the same time - TV and HF radio, perhaps, at a push. The cables are 16mm, ought to be sufficient for the ampage the inverter can theoretically pull (although I'll be running at most 600W through it intermittently).

Also, the leisure battery reads 13.7v-ish when the engine is on, 12.9v when off. Obviously I'd like to run it with it off. The 12.9/12.5v the battery will run at when engine off is within the +/- 15% tolerance of the Yaesu 857d being used, so that shouldn't present too much of a problem, if I'm not mistaken?

Further note: I'll enable the auto switch off feature I've heard the 857d has, if and when this installation happens!


1 Answer 1


There are two things I like to highlight:

1) You are thinking of putting the radio in the same glove box as the inverter; hence you may need extra ventilation/circulation to ensure neither equipment will over heat

2) Usually inverters have fuses built into the inverter, which means that the cables between battery and inverter are unfused (fused at the far end). The best practice for mobile radio installs is to fuse as closely to the battery as possible, you divert from this by connecting the radio directly to the inverter terminals.

In regards to 1) I would not put the inverter in the glove box, nor would I put the radio in the glove box. I would try to find better locations in the vehicle with more (air-)space.

In regards to 2) I would run separate cables from battery to radio, fused as close to the battery as possible. And I would fuse both positive as neutral.

K0BG runs an excellent website with information about mobile installs. I highly recommend a read.

Every transceiver manufacturer, and every vehicle manufacturer, has heretofore recommended direct to battery connections (both positive and negative leads), or to so-called jumps points when the battery is indirectly mounted under a fender well, or trunk area. However, that has changed! All late model vehicles, especially those with EIS (Engine Idle Shutoff), have a battery monitoring system. Typically, these systems use a Hall device to measure battery current drain (Electronic Load Detector). However the wiring is done, it must not circumvent the ELD. A service manual is essential in these cases. As an alternative, your dealer's service manager is a good resource. In any case, both leads should be fused as close to the power source (SLI battery) as possible.

(emphasis added)

  • $\begingroup$ Thanks for the response. The glove box will need to be open when in use with the inverter, and it opens fully into the cab. It also has an open back and some headroom when closed, all near to the footwell fans. So it's not too much of an issue, but I certainly take your point. As for fusing near to the battery, that is probably the best way to reduce fire risks. For the sake of a slightly longer cable run, I'll be sure to directly connect to the leisure battery. As for the k0bg quote, the vehicle is 20 years old, so we're good for ELD :) Was on his/her site just now, as it happens! $\endgroup$
    – luxpir
    Jun 14, 2016 at 15:06

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