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Fish36991 · 01-30-2005, 01:05 PM

Hello All,
First off, this is not my A/S, I'm helping a friend fix it who is in the military and is traveling too much to work on it so bare with me. I don't have the A/S or the manuals right in front of me but I think someone on here will recognize this problem quickly....I hope.

We're having trouble with a 1985 A/S 325 in the electrical system. The A/S is having an intermittent electrical system discharge while driving/running.

Driving down the road, the A/S dash mounted volt meter would go from charging to discharging every few minutes and stay on the discharge side for roughly 30 seconds. Got the A/S home and parked it and it sat for a month or so. Came back to it and the batteries were completely dead...not surprised though.

Put the A/S on the charger to get the A/S running and used the wiring diagram to begin troubleshooting. With the A/S running (ideling or at speed) you could watch the meter jumping from chare to discharge. Under the hood you could hear a clicking. Found the clicking and it was a 30A breaker according to the manual. Replaced the breakers and the batteries (all three) and the problem is still there.

With the drastic change from charge to discharge, it appears to me that it is caused in something that is completely failing. I.E. the Isolator or a switch somewhere. I didn't get to spend much time troubleshooting everything on the A/S because it was getting dark and it's a 9 hour drive each way so I made my best guess and I was wrong. I would really appreciate and educated guess from everyone on here before I make that trip again.

Sorry this is so long but I wanted to give all the details possible and once again...thanks in advance.

Josh

ALANSD · 01-30-2005, 04:38 PM

you could try disconnecting the isolator and see if that changes anything while your vm is on it, at least then you would know which circuit the problem is in, the chassis or the house.
It could be a faulty alternator or regulator or both. What is the charging rate when its working right?. Is there a short in one of the batteries?. Just a few places to start checking, before you get into wiring shorts, etc.

74Argosy24MH · 01-30-2005, 05:14 PM

What alternator? Was it a breaker or relay clicking?

John

Fish36991 · 01-30-2005, 05:17 PM

I know the batteries are okay because we replaced them all and I checked them without the load of the A/S on it. The altenator is putting out around 14V so that should be good. I don't know if it's momentarily dropping voltage but I've never seen that before on any alt. I noticed on the schematics that there is some kind of switching system behind the batteries on the pull-out tray. I'm thinking it's in there or in the isolator. Hope that info helps narrow it down. Any ideas?

thanks by the way for the response.

Josh

Fish36991 · 01-30-2005, 05:20 PM

It was a breaker according to the schematic.

This may help. It's located directly in front of the steering wheel under the hood and is panel mounted to what appears to be a firewall. Standing in front of the A/S it's probably 5 feet up and 1.5 feet from the driver side of the A/S. The schematic called it a breaker...if it would have described it as a relay, it would have been on the top of my list to replace due to seeing MANY relays fail over the years.

Thanks
Josh

Fish36991 · 01-30-2005, 06:44 PM

Also, The owner of the motorhome said there is a airstream motorhome boneyard somewhere in Alabama...has anyone heard of this? If so, please let me know because this may be a good source for parts. Anyone know of any other place to find parts for the Airstream 325? Thanks so much for everyones help.

Josh

overlander63 · 01-30-2005, 07:25 PM

If it is in fact a breaker cutting out, it is because you have an overload or short in that circuit. Check to see what doesn't work in the coach, then start unplugging items in that circuit until the breaker stops tripping, when it does, you have found the problem. It could be a mouse has chewed a wire that is now touching bare metal.
Terry

Fish36991 · 01-31-2005, 07:01 AM

Would the breaker "chatter" like that if there was a hard short or a constant overload. I would think it would just stay open and never reset itself....not sure though. I really don't know how the circuitry in an airstream works or what failsafe systems are in place. That is another possibility added to my list to check though. Thanks. Any other ideas?

Josh

74Argosy24MH · 01-31-2005, 07:25 AM

Quote:

Originally Posted by Fish36991

Would the breaker "chatter" like that if there was a hard short or a constant overload.

That is why I wondered if it was a breaker or relay. Even self resetting breakers usually take 15-30 seconds to reset. Argosy20 probably gave you the best advice, start following the circuit it protects. You have a schematic so that will help, keep an eye out for previous owner mods, they are not always the best.

John

Fish36991 · 01-31-2005, 10:49 AM

The schematic called it a breaker but I honestly can't tell you. The more I read on here it seems that there are few "common" electrical problems. Every A/S has it own little demons here and there that have to be hunted down and taken care of...and I guess this one is no different. There is no difinite right answer when it comes to troubleshooting so I guess I need to accept that it may be me, the airstream, schematics, and my meter spending some quality time together but let me know if something else pops in your head.

You guys have offered some great places to look and for some non-common things to look for. I really appreciate all the help and advice. Since this isn't my A/S I don't know how much I'll be on here in the future but I promise to post the results of the repair on here for everyone so maybe it will help the next guy.

Thanks again everyone, Be safe and I'll report back soon (might be as long as a month),
Josh

59toaster · 01-31-2005, 01:32 PM

Quote:

Originally Posted by Fish36991

I know the batteries are okay because we replaced them all and I checked them without the load of the A/S on it. The alternator is putting out around 14V so that should be good. I don't know if it's momentarily dropping voltage but I've never seen that before on any alt. I noticed on the schematics that there is some kind of switching system behind the batteries on the pull-out tray. I'm thinking it's in there or in the isolator. Hope that info helps narrow it down. Any ideas?

thanks by the way for the response.

Josh

If it's the standard gage on the dash for the Alternator they by GM's wiring that should be before any of the motor home wiring. If its not the alternator then there is a dead short happening and overloading the alternator.

Connect a VOM to the lug on the back of the alternator and see if you see the voltage drop there. If you see drop there then check the wire going to the side of the alternator (usually green). That is the Field wire. It excites the alternator into charge. It gets 12v from the battery when the ig is turned on. Verify its not losing power.

If no drop on the Field circuit and still having the drop on the charge then see if you can get the rest of the non engine related load off and see what happens.

Check the battery cables as well. GM wires in two variations. On some the main cable from the battery will hit the harness feeds for Alternator, Fuse box and starter at the starter. There will be fusible links at that point. In most HD Alternator arrangements there will be a wire directly off the Alternator to the battery instead of joining at the Starter. If it is the Later set up then it is possible that the wire from the battery to the alternator could be corroded and causing these symptoms.

If all that tests out then pull the alternator and have it load tested.

To me it sounds like the Alternator. Last one I had fail had similar symptoms where it would just stop charging.

Fish36991 · 02-01-2005, 03:48 AM

Thanks 59Toaster, (great name by the way)
That gives me a step by step to check this thing out as well as everyone elses suggestions. This should definitely give me a good starting point so I can dive right in as soon as possible.

I really appreciate everyones help, it makes me want to go buy an airstream if the community is this nice. I have a Harley and ya'll have their forums pretty much beat. Anyway, thanks again to everyone and I'll report back and let you know what I find...I'll also let you know if the airstream beats me again!

Thanks,
Josh

Beginner · 02-01-2005, 05:04 AM

Have you repaired the problem? If not Take a picture with a digital camera of this 30 amp relay and email it to me so that I can identify it. Also sent any numbers or letters.

ALANSD · 02-01-2005, 06:07 AM

if the alternator is the problem, your buddy might consider getting a higher amp unit for the replacement. Once you determine if that is it, let us know I can suggest a good source for one not too expensive.

Fish36991 · 02-02-2005, 09:29 PM

Alansd,
Funny you said that, I'll be heading down there next weekend and I wanted to see where we could get a replacement alternator to try and keep as a spare if that isn't the problem. I think that may be one of the hardest thing to get to the airstream on short notice. PLEASE, let me know what you guys suggest for a replacement alternator.....Thanks so much.

Beginner, I can't get pics of the 30A breakers he replaced becasue the airstream is in another state and he's not in either state right now. We'll both be flying in next weekend to try to resolve this problem. I'm 99% sure that the schematics referred to them as breakers and I'm 100% sure that I was on the correct component that matched with the schematic. When he took them into the shop to get them replaced, the employees at the shop even referred to them as breakers so I'm pretty sure they were not relays...at least not called relays in the manual.

I can tell you were they were located. If you were standing in front of the 325 and you have the drivers side headlight pointing at your chest...they are just to the left of the light, under the hood. I don't have the schematic but I do remember that the one that was clicking (chattering or just resetting every 30 seconds) was tied into some switch/selector that I think was located behind the batteries in the tray. The way the tray is built, it was difficult to get in the back side of the tray so I just probed at the other ends of the wires that were connected to the switch/selector.

I know this is long but that's about the best I can recall...if you have any questions, ask away...it may refresh my memory on some more details. Thanks again guys,

Josh

Beginner · 02-03-2005, 04:29 AM

Instead of continuing to shotgun the problem, just look at the offending circuit. First determine which circuit breaker is clicking. This can be done with a digital voltmeter or even a light bulb with two leads. If interested, reply and I will go through the process step by step which will allow you to isolate down to the shorted item.
Beginner

Fish36991 · 02-03-2005, 06:53 AM

Thanks beginner,

I'm not too proud to ask for more help. Any procedure for troubleshooting on the airstream would be great. I'm good with electronics but finding the locations of all the components listed on the schematic is not cut and dry. Board troubleshooting is much easier because all the components are in one place...on the airstream, they're everywhere. Thanks again,

Josh

ALANSD · 02-03-2005, 08:14 AM

I got my alternator through www.4alterstart.com I bought the 135 amp version and it has been pumping out the juice for 18 months or so. Good service form them also. It was a fairly easy install.
Since I went to the higher amp alt, I also replaced the battery isolator with a higher amp version. These guys sell the standard alt as well.

I bought their starter first, which solved the hot start issues.

Fish36991 · 02-03-2005, 08:31 AM

Where did you get the high current isolator if you don't mind me asking? Thanks for the alternator info,

Josh

Beginner · 02-03-2005, 12:22 PM

I can help you with the electrical part.
1. Determine which circuit breaker is opening and closing. This can be done with a digital voltmeter or a light bulb with pigtails. I generally use a light socket from a car tail light or parking light.
A. The circuit breakers that I am familiar with have two posts or threaded studs onto which you place the the two wires, The feed and the load. If you place the multimeter across these terminals (meter range 12 volts DC or better), you will see verry little voltage, usually less that 500 millivolts (mils). If you are using the light bulb, the bulb will not be lit.
B. Start the engine and witness that the charge/discharge cycle is still occuring. As you stated before you heard a clicking that corresponded with the amp meter going from charge to discharge.
C. Try to determine which circuit breaker is clicking by sound if possible. Then test each of the suspected circuit breakers by puting the mulitmeter across the terminals of the circuit breaker. The breeaker that is making and breaking will give you an indication of very low volts then 12 to 15 volts (I hope). Using the light bulb, it will blink on and off. The breakers that are not opening and closing will indicate 0 volts or at least less than one volt/thre light bulb will be out.
D. Once you have determined which breaker is cycling, turn the vehicle off. With the light bulb or the meter check the offending breaker to see if it is energized (hot) with the vehicles key off.
1. If it is not energized remove the LOAD wire. If there are a number of breaker in a row, one terminal the has one or two wires connected to it and the other terminal probally has a metal strip (buss) connecting it to other circuit breakers.
2. If it is still energized, remove the negative battery cable from the battery.
Now remove the LOAD wire. If there are a number of breaker in a row, one terminal the has one or two wires connected to it(the load) and the other terminal probally has a metal strip (the feed buss) connecting it to other circuit breakers.
E. Replace the negative battery terminal if removed and start the vehicle. If the problem has gone away, you have identified the offending circuit. If the problem is still there go through the preceeding steps until you identify the offending circuit and remove the load wires and retest(start vehicle). Next comes the fun part. Figureing out what that breaker feeds. Follow in the vehicke schematic where it goes of follow the harness and see where the wire connected to the circuit breaker leaves the harness and follow it to the appliance that it feeds. Good luck, Good hunting. Let me know how you do.