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Forum
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RE: Shocking! AC power tingle between frame and (real) ground
My uncle was camping in a state park campground and began to hear the next door neighbor's small dog start barking,yipping constantly. They had gone for a walk leaving the dog chained to the metal step on their trailer.
He went to see if he could help,maybe untangle it's chain or something and when he grabbed the chain he got the shock of his life! The trailer frame was apparently "hot" and the poor dog was providing the ground! He pulled the plug from the post and told them what happened when they got back.
The poor dog was freaking out and no wonder. I felt so sorry for it.
Don't know what they found---apparently some problem with the power post itself.
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PaulJ2
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06/16/13 05:00pm |
Tech Issues
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RE: FAIL COLORADO EMISSION TEST
You need to list what part it fails for us to help you. CO? HC? or what.
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PaulJ2
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06/13/13 12:03pm |
Class A Motorhomes
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RE: Dometic fridge will often go in 'check' mode while driving
If you have not done the service suggested in the manual ever it is time. Simple procedure. Rust and crud can drop down and block the flame which makes it easy to go out or blow out.
I agree, rust and crud has blocked what should be a good flame. Makes it easier for it to blow out.
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PaulJ2
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06/13/13 11:57am |
Tech Issues
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RE: Blower Motor won't shut off
The blower fan in a GM does indeed use a relay for it's high speed only. Used to be mounted on the air cond evaporator housing on the firewall, passenger side. Don't know about the later models now. Does sound like it is stuck.
Engine side of the firewall.
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PaulJ2
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06/08/13 09:25pm |
Tech Issues
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RE: Batteries making my rig lean?
You can get into recurring springs as well. Or just move a battery or some of the other loads.
But for movement in side loaded winds, ensuring the inner wheel is no higher in pressure than the outer is critical, and I don't think anyone who has put the pressure a few pounds higher on the outer dually has told me it did not help.
Jim
I have had all this explained this way: Since most roads/highways have a slight "crown" for water drainage etc more of the load is carried by the inner dual tire. Therefore by increasing the air pressure by 4 lbs on the outer tire it increases it's diameter very slightly causing it to carry a more equal amount of the load.
This should equalize the tread scuffing in turns also.
Now this is all big rig stuff but I'm sure will apply to dualies also.
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PaulJ2
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06/08/13 12:43pm |
Tech Issues
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RE: Help with dash a/c-1994 georgie boy pursuit
Most likely looks like a coffee can or a round plastic ball type. I have seen them everywhere from on the firewall, the inner fender on the right and the left, and even behind the front bumper. Start by following vacuum hoses from the engine.
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PaulJ2
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06/04/13 09:51am |
Class A Motorhomes
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RE: gm 8.1 engine
I have a 8.1 in a 2004 PU that used a quart in about 1,000 miles sinse new, now AT 34,000 miles. Changed to Mobile 1 10w-30 synthetic this spring. Took a 3500 mile trip to Arizona and back towing a small TT and it didn't burn a drop! Still on the full mark when I got back! What the heck happened?
Was it the synthetic oil or did it just finally get broken in or what?
Still wondering but happy anyhow. 38,000 miles on the clock now.
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PaulJ2
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06/03/13 03:02pm |
Class A Motorhomes
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RE: AC fan will not start
The start capacitor has nothing to do with the fan. If it spins freely, replace the fan capacitor. (You can double check and try spinning it backwards- if it runs backwards, the fan capacitor is definitely bad)
X2 on this.
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PaulJ2
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06/03/13 12:39pm |
Tech Issues
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RE: Blower quits blowing AC when driving sometimes
If the blend doors are all working, maybe the a/c evaporator is freezing up. Maybe check the freon pressures?
This happened in my brother's S10 once in a trip in high humidity. It would slowly lose flow until there was almost none. Turning the heat on full blast would bring back the flow. Each time we stopped there was a huge puddle of water from the evaporator drain.
Same here. While driving on a hot day the air flow would gradually drop to nothing but a little warm air. Shut of AC for a few minutes and everything back to normal. Checked AC charge, was a bit low but in spec. Topped up the freon charge, no problem since.
99 Jeep Cherokee.
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PaulJ2
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06/02/13 07:13pm |
Tow Vehicles
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RE: Converter On/Off-In-Rush and Capacitor Unloading-Reloading?
The switching supplys I was involved with had a working voltage of 260 volts. The large filter caps were 500V rated, the small .1mfd filters were 1000V rated. We very seldom lost one.
Agree with above, it's mostly about the quality of the parts.
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PaulJ2
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05/31/13 10:30am |
Tech Issues
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RE: Converter On/Off-In-Rush and Capacitor Unloading-Reloading?
Thanks, so are you confirming that it is bad to restart "too soon" before the caps have unloaded?
If so, can you clear up whether the DC voltage tapering down on shut off is related to that unloading so that its timing will be an indicator of when it is "safe" to restart?
Yes I get a good snap on start-up sometimes, not always. Scared me at first, being gun-shy from wrecking my previous 100amper :(
Thanks!
When power is removed the caps should discharge at a rate equal to the time it takes for the thermister to again increase to it's cold resistance value. A bleeder resister is selected sometimes to get this right. Therefore tapering down the load should have little to do with this as this is all involving the input circuit.
A switching supply operates until it's input voltage drops below some spec then collapses to zero immediatly.
I suspect that in todays world they manufacture lots of these quickly and if some fail---oh well they will give you another one.
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PaulJ2
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05/29/13 06:06pm |
Tech Issues
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RE: Converter On/Off-In-Rush and Capacitor Unloading-Reloading?
Hi BLF,
I have had an oppertunity to repair as many as 20 to 30 converters over the last couple of years.
90% of the failures have been the input side 250Vdc 1,000ufd caps (typically there are at least three in parallel). Most switching converters ingest the 115VAC then with a full wave bridge rectifier get about 160VDC on the input side of the switching supply.
Yes from what I have seen plugging and unplugging the source AC supply has contributed to the failures. That said many were defective caps in the first place. I would venture a guess that your thermister was previous to the bridge rectifier on the AC side of things. Surge currents do strange things and are NEVER any good for electronics devices.
I worked on switching supplys for many years on my former job.
Most failures are from a defective under rated component or a just plain poor cheap design to start with. Inrush current is always a problem to deal with and with proper design is not an issue.
As you know the current to charge up the caps creates the main surge and has to be limited. Usually a thermister, some .1mfd caps and a transformer/coil or torid is involved.
The caps absorb the very high,quick peaks of the current and the thermister and usually a 5 ohm series resister help limit the current until it is up and running, then the thermister resistance drops to zero. A torid or 1-1 transformer coil is usually in series which has two functions. It's main job is to filter out the aprox 20 khz operating frequency that can go back into the power line. However it also adds a bit of inductance to 60 hertz and helps with the inrush limiting.
If the circuit design leaves some of this out you can expect trouble sometime.
Ever notice that when plugging in you converter/trailer plug you will get an arc/snap sometimes and not others? It just means you caught the 60 hertz cycle at mid point (no current) or at the peak (max current). I know, more than you want to know.
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PaulJ2
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05/29/13 01:56pm |
Tech Issues
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RE: Help please!
I'm new to the rv world. If "shore power" is the term used for hooking up to electric outlet, then yes, I am plugged directly into my home and was plugged in when it quit working last fall.
Yes - shore power means hooking into outside AC outlet. Are you sure that the house outlet is working and that the RV load didn't blow a house fuse?
X2
Before we all get lost here---are you sure the outlet at the house is working?
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PaulJ2
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05/22/13 12:14pm |
Tech Issues
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RE: Re-packing bearings
No matter ever which way you do it there needs to be a tiny bit of play when you are done to allow the grease to get between the rollers and the race.
No play? Metal on metal and overheating.
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PaulJ2
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05/21/13 05:53pm |
Tech Issues
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RE: 12 volt issue
Your second picture shows some green corrosion on the negative terminal. So yes I believe you found your problem.
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PaulJ2
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04/22/13 07:25pm |
Tech Issues
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RE: Awning damage from unfurling
Happened to us while driving into a gusting wind east of Reno. I caught it just as about 3--4ft had rolled out and was flapping on top of the roof. The arms were still safely locked in place on the trailer.
I rolled it back up and used a heavy duty bungy strap that I had, by sticking the end into the hole on the roller end cap, pulling down tight on it and rapping it around the arm. Finished the trip this way with no problems.
After I returned home I decided to investigate some more. I noticed I can pull it out--click-click-click regardless if the "lock" lever is in the lock position or not. All the lock does is keeping it from rolling back in.
I assumed this is normal but maybe not. I do like the rod "fix" that Old Bisket
uses.
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PaulJ2
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04/21/13 08:47pm |
Tech Issues
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RE: Is this only an Arizona issue ????
Yes, I think it is an Arizona issue. Several years ago we pulled into a shopping center parking lot and parked at the very far end of a row with no cars near by. Since I was towing my small TT it was so I could easily get out.
My truck was new at the time also. As my wife got out and walked around the front to meet me we heard a loud "WHAM" and the whole truck shook. Walked back around to the passenger side and a Jeep had backed into the side, caving in the bed and fender---NO DRIVER. It had rolled about 100ft down a slight slope through the entire parking lot backwards and yup, into my truck.
As we walked back up to where it came from here came a confused guy looking for his Jeep. His comment was---I guess I didn't set the brake.
Yup, and wasen't in gear either!
Anyhow, his insurance CO was in the same shopping center so we settled all the paperwork and went on our way. Repaired the damage after I returned to my home state a few weeks later. Was in Wickenburg.
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PaulJ2
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04/16/13 12:15am |
Tow Vehicles
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RE: Need help with Air Conditioner / Hard Start Capacitor issue
Without getting into heavy duty theory here--starting capacitor sizes are picked to function with a certain motor depending on the internal resintence of the starting windings,it's wire size and etc, etc. So too much capacitence is as bad as too little.
So adding the capacitor is probably taking it too far from it's
optimum value.
I also don't see the PTC motor starting device in your second picture. This needs to be in the circuit also.
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PaulJ2
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04/14/13 05:12pm |
Tech Issues
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RE: Air conditioner wattage
I usually figure about 3 times the running amps for starting most motors. LRA of course means a stalled motor, and this is usually a fraction of a second during starting.
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PaulJ2
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04/11/13 10:41am |
Tech Issues
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RE: EcoBoost Gas Mileage
Any vehicle with 6 cylinders moving a similar amount of weight will get about the same mpg. Doesen't matter if you have one turbo, twin turbos, or no turbo.
The eco-boost just means you have the option of much more power, can burn much more fuel, and all in the same vehicle.
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PaulJ2
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04/10/13 05:46pm |
Tow Vehicles
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