JDRV SERVICES INC. RV and Marine Parts and Accessories



Slideroom leaks when it rains???
Something that has come to my attention is the slide rooms. On the roof of the fwd slides there is a trim piece that is installed where the roof of the slide meets the side walls(short walls) this trim is adhered with sika flex and in some coaches the metal was not treated properly prior to application.The stress on this joint when the slide operates causes a good amount of flex and may cause the trim to come loose. This will create a pretty good funnel for rain water to get into the walls of the slide and cause severe damage. A good inspection can save a lot of heart ache.

2 piece door check

Now that we have successfully refined the one piece door check. We are ready to start on manufacture and testing of the two piece door check (shown in the photo above)
But I am in need of an old one to use for design and messurement. If you have one available that can be used for a model, please contact me right away.

Echo Chargers
 Q: How does my echo charger work?
 A: The echo charger is designed to allow a maintance charge to pass over from the house batteries to the chassis batteries to maintain a stable state of charge.
 But be aware that it is not designed to charge a dead battery/batteries.
 So lets talk about how it works.
 The following are excerpts from the echo charger manual:

The Xantrex Digital echo-charge is specially developed for charging an

auxiliary battery with FreedomTM or Fleet Power Inverter/Chargers or with

any charging source. The Digital echo-charge automatically switches ON

and OFF, charging a starter or auxiliary battery without affecting the main

house battery bank. The maximum charge current is 15 amps when the

starting battery is 1/2 volt to 1 volt DC less than the house battery. The

Digital echo-charge is designed to work on 12 VDC or 24 VDC systems.

The Digital echo-charge is a voltage-follower, following the three-stage

charge modes of the Freedom Charger. This method protects the starter

battery from over-charging and ensures a long life for the battery. If using

another charge source, the Digital echo-charge will follow the charge

stages of the source.

When the input voltage is 13.0/25.5 volts DC or higher, echo-charge

automatically switches ON. The LED glows a steady green. When the

input voltage is lower than 13.0/25.5 volts, the echo-charge automatically

switches OFF, and the LED blinks green. The output voltage of echocharge

is limited to 14.4/28.8 volts. When it reaches 14.4/28.8 volts, the

charge current will decrease, maintaining a float condition. The starter

battery will be fully charged without overcharging.

No load current drain on the house bank is less than 50 milli-amps.

If the input voltage is above 14.4 volts (or 28.8), output will be limited to a

maximum of 14.4/28.8 volts.

Lets talk about "INVERTERS".

Combi series

Pure sine wave as opposed to modified sine wave
AC (Alternating Current) electricity involves electrons that move back and forth in a wire. However, they do not move in one direction, then instantaneously stop, then move in the other direction, then instantaneously stop, then move back again, ... Instead they move in one of two ways: as a true/pure sine wave or as a modified sine wave.
- True/pure vs modified sine wave -
True/pure versus modified since wave.

With a true/pure sine wave they accelerate in one direction until reaching top speed and then decelerate in the other direction until they stop and then they change direction and accelerate in that direcition until reaching top speend and then decelerate in the other direciton, ... The result is a very smooth movement as in the graph on the left above. The electricity you get from the power utility company is like this.

A modified sine wave, on the other hand, is not even a sine wave. It's really a modified square wave. In this case the electrons very rapidly speed up and continue at that speed and then rapidly speed up again and continue at that speed and then rapidly slow down and continue at that speed and then rapidly slow down again and then stop for a while. They then repeat all this in the other direction, ... The result is a very jerky movement as in the graph on the right above.

The problems

All appliances work with pure sine wave inverters. However, some may not work with modified sine wave inverters:

  • may cause buzzing sound with some cheap stereos and ceiling fans;
  • some digital clocks will not work;
  • inductive motors, as found in some power tools, may not work properly.

The problem with pure sine wave inverters is that they cost more than modified sine wave inverters, anywhere from a few hundred to thousand dollars more. If you have a system for cottege use, you may be less picky in your selection of appliances but if the system is for your primary residence then you'll want a pure sine wave inverter. Low power pure sine wave inverters of less than 1000 watts used to be hard to find but are available nowadays.

Q: Can I leave my inverter on all the time.
A;Yes you can, BUT, let's talk about what an inverter does and why.
    An inverter uses a transformer system to create an alternating current sine wave in order to operate 120 volt appliances.
    So... if you are inverting 120 volts from 12 volt batteries guess how long it will take for them to go dead.  " Not long" (it will vary depending on the age and quantity of batteries you have).
   Try to think about your inverter this way and see if it helps:
    Its 3 am and you just pulled in to that RV park.Its Raining like the dickens outside and its to late to run your gen set.Yet you would like a cup of hot cocoa and some tv to wind down after a long days drive.
    Well you're in luck. You have an inverter run the tv, vcr, satellite, microwave, or coffee pot no problem. BUT, remember you need to put this power that you are taking out tonight back in in the morning.
     Plug in or run the gen set for a minimum 1 hour for every 4 hours you used the inverter last night.This will help to make sure you never have a dead battery due to inverter use.
     Now for those full timers who hate to reset your clocks every time you unplug to move; if you are full timers and are plugged in more than not, leave your inverter on, it wont hurt a thing.  In fact it is a good thing because it will monitor your batteries and help them last longer provided you maintain the water level. But that is a subject for a later bulletin, (let's leave it at; check battery water level every 30 days ).Dont be afraid of your inverter use. Enjoy it...you paid for it.
   Happy camping

Email us with any questions you might have.

Thank you.


 All pre-approved returns are subject to a 30% restocking fee. Please call for Return Goods Authorization number (RGA). Shipping and handling charges are not refundable. All refused shipments or returns without pre-approval are subject to a 35% restocking fee. There are no returns allowed of Carburetors, Heat Exchangers, Cooling Kits, Electrical Items, Starters, Alternators and Engines (partial or complete). Special orders cannot be cancelled or returned. Any item older than 30 days, not in original packaging or was installed is non-returnable. Please refuse any package/shipment that is received damaged. All hidden or concealed damages or shortages MUST BE reported within 24 hours of receiving your shipment. All items are subject to the manufacturers limited warranty only. JDRV Inc. an jdrv1.com shall not be responsible for incorrect parts ordered.


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