Home » Public Forums » GMCnet » Onan - No AC Outpus
| Re: [GMCnet] Onan - No AC Outpus [message #246462 is a reply to message #246460] |
Sat, 05 April 2014 12:10   |
Don A
Messages: 895
Registered: October 2008
Location: Dallas, TX
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Steve maybe a pic of your meter?
Even the free Hnr Freight meters have a diode function down at the bottom with with the arrow and bar symbol.
Don Adams Dallas, TX
'76 26' Glenbrook, '90 Sidekick
rebuilt by R Archer, powered by J Bounds, Koba
[IMG]http://www.gmcmhphotos.com/photos/data/6109/G2.jpg[/IMG]
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| Re: [GMCnet] Onan - No AC Outpus [message #246463 is a reply to message #246460] |
Sat, 05 April 2014 12:11 |
Steve
Messages: 506
Registered: September 2013
Location: East Greenville, Pa
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| Steve Adams wrote on Sat, 05 April 2014 12:49 |
| Dave Mumert wrote on Sat, 05 April 2014 12:33 |
Hi Steve
Some meters use a low voltage for resistance measurements, low enough so as to not cause diodes to conduct. That is so you can
measure resistance in circuit without getting errors caused by diodes, or transistors in the circuit.
Does your meter have a diode function?
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Dave, I don't know that it does. It is a pretty simple unit. I have a nicer one with more functions including auto ranging but it is not working properly (either that or I am not smart enough to figure it out).
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Dave, a quick internet search leads me to believe that my meter does have a diode test function. The symbol is like an arrow and a plus sign together.
When I test the BR on that setting I get an Over Load in one direction and a reading of about 523 in the other direction. On that setting and trying to understand how a diode works, it would seem that maybe my BR is functioning properly?
1978 GMC Royal
Eastern Pennslyvania
1968 Chevrolet C20 396 Camper Special
1969 Chevrolet C20 Camper Special
1985 Buick Electra Park Avenue
1992 Camaro 25th Anniversary Heretage Edition Black
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| Re: [GMCnet] Onan - No AC Outpus [message #246471 is a reply to message #246452] |
Sat, 05 April 2014 13:58 |
Jim Miller
Messages: 501
Registered: March 2008
Karma: 10
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On Apr 5, 2014, at 11:40 AM, Steve Adams wrote:
> Bridge Rectifier (BR) testing results: [...]
Steve,
The 38 ohm result is very good news.
Have you confirmed that your field wiring to the BR is correct? Specifically that the field lead labeled F1 goes to + on the BR? The leads have F1 and F2 printed in their insulation along its length.
I would not be too quick to condemn the BRs based on your tests - it is *extremely* unlikely that all four diodes in each of your BRs are failed.
Digital meters used for diode tests can give all sorts of wacky results so I suggest just trying a new BR or if you really want to test the old BRs then just use a battery and a 12V bulb instead of a meter. The tests many of the guys have been describing work well with older analog meters but not so well with modern digital units that use different measurement techniques internally.
--Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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| Re: Onan - No AC Outpus [message #246474 is a reply to message #245891] |
Sat, 05 April 2014 14:38 |
Steve
Messages: 506
Registered: September 2013
Location: East Greenville, Pa
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Thanks Jim,
I will try the battery and light test just to satisfy my own curiosity. I have been reading more on BR's and diodes. Yes, I was very happy to see 38 ohms on my unit, but not sure where to go next in terms of testing other than the BR's and field?
I have also reviewed some diagrams trying to better understand how to test the AC voltage. I found some old threads where you had indicated to just test it inside the coach, which is what I have done in the past, but I am now trying to measure voltage at the breaker. It makes no sense to me to check AC voltage by measuring a hot and a ground to the onan case. That's how I would think about and check DC but I have always thought about two wires to check AC, hot and neutral.
I am going to put the BR back in and try to measure AC voltage again. I am pretty sure I have the wiring correct because as you mentioned the wires are coded as F-1 and F-2. My other two wires are one black and one white and I marked those colors right on the side of the plastic socket before I took the wires out of it so pretty sure the AC wires are correct. If I understand what I have read about BR's it should not even matter if they are in the right place as the BR would correct the polarity?
1978 GMC Royal
Eastern Pennslyvania
1968 Chevrolet C20 396 Camper Special
1969 Chevrolet C20 Camper Special
1985 Buick Electra Park Avenue
1992 Camaro 25th Anniversary Heretage Edition Black
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| Re: [GMCnet] Onan - No AC Outpus [message #246478 is a reply to message #246474] |
Sat, 05 April 2014 15:31 |
mickeysss
Messages: 1476
Registered: January 2012
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the 6 tab has the circle part at the bottom and has no wire. no 4 tab as well. do not get 6 and 9 mixed up, 9 has circle towards the
top. on the board. most the time the board and the board rectifier is not the problem.
%40 of the time it is the board. mine was the 5 amp 31 volt fuse. if it is 110 the fuse in the top green box back middle has a button to reset the 110
which may be caused by shutting off the onan with the a/c still running which is a no no. turn off all electricity before shutting it off.
turn off the hot water heater before anything. This is what duanes dvd states, i think, but take these ideas as points of view not science faith do it's. the br has to be marked right before you take it apart because it can fit 4 ways. good luck. i have not read most this thread but thought maybe something i just did may help. Mic disneyland, 77 palm beach
you check the 110 by poking a pin hole in the fat white wire at the top box on both sides and ground it to the O. ground bolt or any frame really and see if it is running if it has 110 on both sides the fuse works, in only on the side towards the front of the gmc then the large fuse button of switch needs to be reset. you may know all this already. but maybe some of it may help. sorry if i take up your time.
If 5 and 9 does not make the gas pump make noise, the fuse behind all the wires a 5 amp fuse is blown and i had to use a magnifying glass to see it broken. If you have run around this block already sorry. it must be a 32 volt 5 amp fuse for it is the fuse to the br. from the voltage regulator which are the three wires top behind the cab, that should be two wires on one tab together and one wire in front top of it, these wires should not ever touch each other but taken off the regulator and taped separately and mooted out of the way. You do not need the regulator at all for it is obsolete to the system. This way the onan finds it's voltage faster to 32 volts to the board and starts. If you get the dvd of duane simmons he explains all this very well and shows you where it all is.
if you have 110 at the onan but not in the gmc, it could be the plug for house 110 is not plugged in as well right? on the side door above left facing the onan. I think. i am just learning this stuff and trying to see what the hell is going on.
mic
it you know how the br old one was in put it back it most likely still works according to duanes dvd. it is a small percentage of the time it goes bad. it gets hard to put it back it seems once out and just clean it all could be it with 2-26 cleaner. try it again.
On Apr 5, 2014, at 12:38 PM, Steve Adams wrote:
>
>
> Thanks Jim,
> I will try the battery and light test just to satisfy my own curiosity. I have been reading more on BR's and diodes. Yes, I was very happy to see 38 ohms on my unit, but not sure where to go next in terms of testing other than the BR's and field?
>
> I have also reviewed some diagrams trying to better understand how to test the AC voltage. I found some old threads where you had indicated to just test it inside the coach, which is what I have done in the past, but I am now trying to measure voltage at the breaker. It makes no sense to me to check AC voltage by measuring a hot and a ground to the onan case. That's how I would think about and check DC but I have always thought about two wires to check AC, hot and neutral.
>
> I am going to put the BR back in and try to measure AC voltage again. I am pretty sure I have the wiring correct because as you mentioned the wires are coded as F-1 and F-2. My other two wires are one black and one white and I marked those colors right on the side of the plastic socket before I took the wires out of it so pretty sure the AC wires are correct. If I understand what I have read about BR's it should not even matter if they are in the right place as the BR would correct the polarity?
> --
> 1978 GMC Royal
> Eastern Pennslyvania
> 1968 Chevrolet C20 396 Camper Special
> 1969 Chevrolet C20 Camper Special
> 1985 Buick Electra Park Avenue
> 1992 Camaro 25th Anniversary Heretage Edition Black
>
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| Re: [GMCnet] Onan - No AC Outpus [message #246480 is a reply to message #246474] |
Sat, 05 April 2014 15:46 |
Jim Miller
Messages: 501
Registered: March 2008
Karma: 10
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On Apr 5, 2014, at 3:38 PM, Steve Adams wrote:
> I will try the battery and light test just to satisfy my own curiosity. I have been reading more on BR's and diodes. Yes, I was very happy to see 38 ohms on my unit, but not sure where to go next in terms of testing other than the BR's and field?
After the BR and field comes the reactor. But don't worry about that yet, reactors are a low-rate-of-failure item.
> I have also reviewed some diagrams trying to better understand how to test the AC voltage. I found some old threads where you had indicated to just test it inside the coach, which is what I have done in the past, but I am now trying to measure voltage at the breaker. It makes no sense to me to check AC voltage by measuring a hot and a ground to the onan case.
Measure between the two AC wires coming out of the Onan. Measuring a "hot" against the generator's case is meaningless.
Unless you suspect interior wiring problems then I'd take my measurement at an AC outlet inside the coach somewhere.
> If I understand what I have read about BR's it should not even matter if they are in the right place as the BR would correct the polarity?
The orientation of the AC wires on the BR do not matter. The orientation of the DC wires certainly do.
--Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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| Re: Onan - No AC Outpus [message #246491 is a reply to message #246474] |
Sat, 05 April 2014 19:55 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| Steve Adams wrote on Sat, 05 April 2014 13:38 |
Thanks Jim,
I will try the battery and light test just to satisfy my own curiosity. I have been reading more on BR's and diodes. Yes, I was very happy to see 38 ohms on my unit, but not sure where to go next in terms of testing other than the BR's and field?
I have also reviewed some diagrams trying to better understand how to test the AC voltage. I found some old threads where you had indicated to just test it inside the coach, which is what I have done in the past, but I am now trying to measure voltage at the breaker. It makes no sense to me to check AC voltage by measuring a hot and a ground to the onan case. That's how I would think about and check DC but I have always thought about two wires to check AC, hot and neutral.
I am going to put the BR back in and try to measure AC voltage again. I am pretty sure I have the wiring correct because as you mentioned the wires are coded as F-1 and F-2. My other two wires are one black and one white and I marked those colors right on the side of the plastic socket before I took the wires out of it so pretty sure the AC wires are correct. If I understand what I have read about BR's it should not even matter if they are in the right place as the BR would correct the polarity?
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Steve, you are at the point that it will be nuch easier to put in a new $5 rectifier than go any further. Gene's site has a way of converting a high power unit off ebay to fit your coach. I have several but it will cost more to ship it than you can buy one for.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Onan - No AC Outpus [message #246492 is a reply to message #246480] |
Sat, 05 April 2014 20:02 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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the main bolt in the floor behind the right side of the onan is the main ground for onan. I got mine running just now after replacing the fuel line that was very very bad, very out of place being all other parts are new. pump, gas line to big tank? where did this carb line come from? Ben laden? the rest of everything now with the line fixed is like new the a/c went on cold as it could be with ac on the sample plug tester was good all over the gmc. it got cold in there in about 20 to 30 minutes had my first lunch with the air and onan running and it is rather quiet inside. the muffler manifold gaskets are new, i cannot understand how this gas line got on there? good old pep boys had the duane simmons kiss parts for the gas line with leak wrap and they were airtight. i did not have 110 inside because the plug was not plugged into the onan in the door just to the left of the onan with the keyed door. I did not plug the house into it when i started it and it ran great idled about
1800 just like it should text book really, then i turned it off and plugged the onan into the house or vice versa and went in and tested the 110 plugs all good and then turned on the a/c low then med. then high and bingo what a great little space ship on earth they are. i thank you Ken Burton for all your help. I tested my house battery up front and it was getting 13.2 from the buzz box i suppose which i cannot find yet but it charged the battery from 12.3 to 12.5 while i had lunch in the a/c, whoopee what a day. Mickey anaheim ca. 77 palm beach and onan!
On Apr 5, 2014, at 1:46 PM, Jim Miller wrote:
> On Apr 5, 2014, at 3:38 PM, Steve Adams wrote:
>
>> I will try the battery and light test just to satisfy my own curiosity. I have been reading more on BR's and diodes. Yes, I was very happy to see 38 ohms on my unit, but not sure where to go next in terms of testing other than the BR's and field?
>
> After the BR and field comes the reactor. But don't worry about that yet, reactors are a low-rate-of-failure item.
>
>> I have also reviewed some diagrams trying to better understand how to test the AC voltage. I found some old threads where you had indicated to just test it inside the coach, which is what I have done in the past, but I am now trying to measure voltage at the breaker. It makes no sense to me to check AC voltage by measuring a hot and a ground to the onan case.
>
> Measure between the two AC wires coming out of the Onan. Measuring a "hot" against the generator's case is meaningless.
>
> Unless you suspect interior wiring problems then I'd take my measurement at an AC outlet inside the coach somewhere.
>
>> If I understand what I have read about BR's it should not even matter if they are in the right place as the BR would correct the polarity?
>
> The orientation of the AC wires on the BR do not matter. The orientation of the DC wires certainly do.
>
> --Jim Miller
> 1977 Eleganza II
> 1977 Royale
> Hamilton, OH
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
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