jeffw Posted August 18, 2021 Report Share Posted August 18, 2021 Hi: Our race trailer has (had?) a Onan QD7500 that died over the weekend after 20 years of faithful service. I'm trying to figure out what to do as a replacement, but one thing I'm considering is a gas Honda (the big boy eu7000is) placed on our truck bed and using it to power the trailer. I remembered some folks had interesting mounting/enclosures to put a generator on the truck frame. Our truck used to have an APU, so I've got plenty of room on on the passenger side. But, I'm wondering how to protect the generator from the elements, and also allow it to run in some sort of enclosure w/o overheating. Also, access to both sides of the generator for maintenance would be a concern. Does anyone have the 6500/7000 mounted on their truck? Could you share some photos? thanks! -jeff Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jkoenig24 Posted August 18, 2021 Report Share Posted August 18, 2021 How many hours are on said dead generator? Are you sure that the current "dead" Onan unit can't be rebuilt and resurrected? What would it cost for an actual Cummins shop to look it over? Quote Link to comment Share on other sites More sharing options...
Darryl&Rita Posted August 18, 2021 Report Share Posted August 18, 2021 Short of a rod through the block, I'd stick with the QD. Quote I have been wrong before, I'll probably be wrong again. 2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication 2006 smart fourtwo cdi cabriolet 2007 32.5' Fleetwood QuantumPlease e-mail us here. Link to comment Share on other sites More sharing options...
noteven Posted August 18, 2021 Report Share Posted August 18, 2021 5 minutes ago, Darryl&Rita said: Short of a rod through the block, I'd stick with the QD. I’m with this opinion ^ . It can be quite a bit of work to adapt a portable generator to an enclosed vehicle mount. Controls, cooling air, fuel, noise, protecting the generator from vibration from the truck frame during travel, water… If your Onan is not repairable a call to a RV wrecker or two might turn up a low hour replacement. Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
trimster Posted August 18, 2021 Report Share Posted August 18, 2021 I put a Champion generator in a custom enclosure behind the rear axles. Had a local fab shop create an enclosure with a slide out tray (to service the generator) and holes for airflow, a radiator fan to suck air through the cabinet, etc. Now, after a few months on the road, I've leaned a ton. The up and down forces on the generator are massive. The generator jumps up and down (90lbs) and ends up sideways in the cabinet. I strapped it down with trucker strength bungies and that didn't stop the movement. I now have it strapped in with webbing. If the truck were singled, I would have mounted the genny and cabinet in front of the axles. More like where an APU is typically mounted. The generator cabinet is beefy steel with fish-plated top section. The cabinet is basically hung in place with additional supports down the front side to stop any swinging movement. It has help up very well under some brutal roads. I would like a diesel generator, but that was not in the budget. I added a 7 gal gas tank above the cabinet (under the bed deck) for additional run time. Quote Robert & Lisa '14 Keystone Fuzion 315 38' 5er 2015 Volvo VNL 670, D13, iShift 'The Tartis' (ours) 2013 Smart Fortwo Passion 'K-9' 2011 CanAm Spyder RT Limited (Ours) We are both USAF vets. Link to comment Share on other sites More sharing options...
jeffw Posted August 19, 2021 Author Report Share Posted August 19, 2021 So a bit more info on the QD.... We bought the trailer used in 2016. It was a 2008 model year trailer, but the generator manufacturing date was from 2000, so we suspect the previous owner had the generator 'laying around' and put it in. The hour meter was broken when we got it, stopped at 1368 hours. This generator is an inverter generator with 2x35A 120V legs. Last year, one of the legs dropped to ~60V and I contacted a local Onan dealer and they came to look at it. He said it's likely the inverter board, which is $1500, and the generator has to come out of the compartment for service, which is not straightforward. I think he said to figure $1k in labor just for removal/reinstall of the generator from the compartment. The trailer load is way less than 35A, so I rewired the one working leg to support all of the circuits in the trailer and limped along for the next year. This weekend, the lights started flickering a bit, and then eventually shut off. If the generator sits a bit, I can restart it and it'll work for a few minutes and then shut off. The engine does run fine--no smoking, starts up great. I do like the convenience of the generator but I'm worried about it becoming a money pit considering it's 20 years old. Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
Steve from SoCal Posted August 19, 2021 Report Share Posted August 19, 2021 Inverters have capacitors that can fail, one of the more common failure modes for inverters. You may want to do a bit of investigating before tossing it. May not be the generator you use right now but if the caps failed and they are source able the fix is not that difficult. There are places that do board level repair on all kinds of stuff from welders to CNC controls. If the thing is not a smoking pile don't just toss it arbitrarily. Quote 2005 Peterbilt 387-112 Baby Cat 9 speed U-shift 1996/2016 remod Teton Royal Atlanta 1996 Kentucky 48 single drop stacker garage project Pulls like a train, sounds like a plane....faster than a Cheetah sniffin cocaine. Link to comment Share on other sites More sharing options...
jeffw Posted August 19, 2021 Author Report Share Posted August 19, 2021 I just met with a local Onan dealer/shop and our plan is to pull the generator in a couple of weeks and see what's broken on it, and then make a decision on repair/replace. He's hopeful it might not be the inverter but something cheaper. Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jeffw Posted September 27, 2021 Author Report Share Posted September 27, 2021 A bit of an update....we pulled the generator out a week ago, which took about an hour and half (and a forklift). Initial news seems promising. Internally the generator is still producing 120V on both of the circuits. Apparently the previous owner apparently did a bad repair to the area where the generator output connects to the trailer. One of the circuits was melted and the other damaged. The plan is to repair that and do the 1000 hour service and put it back into service. Was very glad to hear it wasn't the inverter board or alternator. Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
Imurphy907 Posted October 1, 2021 Report Share Posted October 1, 2021 Well that's good to hear. Quote 2016 Road Warrior 420 2001 Volvo VNL 660 Alaska Based. Link to comment Share on other sites More sharing options...
noteven Posted October 2, 2021 Report Share Posted October 2, 2021 Are you still planning a relocate to the truck? I'll bet there is tech available to make controlling it from the trailer a wireless affair. Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
jeffw Posted October 3, 2021 Author Report Share Posted October 3, 2021 No, it's going to go back in the trailer....makes the most sense there (though service for big things is certainly a challenge). Hopefully meeting at the shop Sunday morning to get it reinstalled. Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
LRKDRV7.3 Posted October 4, 2021 Report Share Posted October 4, 2021 Mounting a generator behind rear wheels is sketchy. Road debris dust etc if going north salt will destroy circuit boards......you do not want to learn the way i did Quote Link to comment Share on other sites More sharing options...
jeffw Posted October 4, 2021 Author Report Share Posted October 4, 2021 We got the generator re-installed today and it seems to be working well. The repair was 11 hours (including 3 hours labor for removing/reinstall) and around $700 in parts for the repair and the 1000 hour service. Hopefully good for another 10 years 🙂 Quote 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
lockmup68 Posted November 23, 2021 Report Share Posted November 23, 2021 I had to put a new head on my QD8k as the controller board is soldered to the head. It was about $2500, but the Kubota diesel just keeps cranking. I have about 300 more hours on it now and happy with the repair. New QD8k is about $10k. Also, I have it mounted between the frame rails behind the rear axle on the truck. Been like that for 10 years. I've owned the truck for 5. Quote 2003 International Eagle 9200i, Cummins ISX, Freedomline 2007 Teton Scottsdale XT4 Link to comment Share on other sites More sharing options...
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