When I first connected the AIU all switches worked and tested ok. The only thing I have changed on the layout is I've put the TIU's in super mode. The second AIU is working fine, but the first will not. I would seem that although I can hear the relays they are not passing any power. Is my AIU toast?
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If the relays are clicking, the AIU is functioning. The circuits they control are all independent. Most likely cause is that the power to the center terminal of the relays is disconnected. How do you have them wired?
When I first connected the AIU all switches worked and tested ok. The only thing I have changed on the layout is I've put the TIU's in super mode. The second AIU is working fine, but the first will not. I would seem that although I can hear the relays they are not passing any power. Is my AIU toast?
Does the "read" find both tiu and both aiu?
Gregg,
Does the "read" find both tiu and both aiu?
If the READ couldn't find it, the relays wouldn't click.
Well you're probably right , but I still would try the read as a first step. I want to see it. i'd also try putting the tiu back in normal mode.
Gregg,
The READ command moves all non-powered engines straight to the Inactive Engine List. This can, under DCS releases prior to 4.30, cause engines to become stuck in the Inactive Engine List in a multiple TIU environment.
For this reason, I typically avoid using the READ unless it's explicitly called for, i.e., when a TIU or AIU is non-responsive or cannot be found. Even then, when attempting to determine if a remote can access a TIU, I suggest attempting to learn the version of a TIU's software rather than doing a READ. This is a "non-invasive" way to determine whether or not the two are connected.
I have tried the "READ" and all TIU and AIU units are found. Everything is at DCS 4.20. This is a rebuild so at this point there are only 3 engines programed. 1 DCS, 2 TMCC. Power is supplied by a separate Z750. All switch lights work, all switches throw when I jumper them. The AIU in question is 1 and AIU 2 is performing flawlessly. So far only switches are connected. Tested for ops of ACC on AIU 1 using meter and it read 0.0L for ports 1, 2 and 10 regardless of soft key pushed. Hope I covered all the bases, pheww.
Thanks for any help, it is appreciated.
P.S. I tried putting TIU 1 back to normal and no change. Thanks.
If the relay coil clicks on,most likely the contacts are burned out. (assuming it is wired correctly). I think these AIU relay contacts are rated at 4 amp and circuit protection is often 10 amps. In a short circuit or just too much amperage, these contacts can be fried. If you are switching heavier loads,I suggest hooking the relay contacts to power another relay coil,with higher contact ratings to power switched accessories or lighting.
Dale H
All 10 at once! 
Only FT switches, and I only throw one or two at most at a time. I don't see anything in the system that would draw 4amps or more. 
No that is no likely. Check your wiring and common power source. Tripped breaker etc, Disconnect a relay outlet contact set and check continuity with a meter when the relay clicks. I assume the sound you hear is a relay clicking shut. Put meter on an ohm setting put leads across C and NO of the relay outlet. Should read 1 or open, with relay off. Energize the relay,meter should go to zero. That means the contact is good and working. Problem is elsewhere in your wiring then.
Dale H
That was done and the meter read 0.0L. The switch wiring works fine until it goes into the AIU. There are no tripped breakers. Bricks are working fine. Thanks for the input though, will keep checking things as new ideas come up.
Do you use both the AIU and a control panel to control switches? What switch lights that work are you talking about? What brand switch motoros are you using?
Personally, I find it hard to believe that all 10 pairs of contacts would fail. I'll ask again, how do you feed the "IN" terminals on the AIU for the switches?
You say your meter reads 0. To what are you connecting it?
OK,
1. These are FasTrack switches, no controllers, lights on switch itself.
2. Tested for continuity with meter at AIU putting black lead on in and red lead on 1 or 2 and switching switch with DCS Handheld and getting (and I'm quoting the Meter) 0.0L.
3. All switches are wired for AUX power being provided by a Z750.
And...
4. I'm finding it hard to believe all 10 switch ports are bad, and it would seem ACC ports too.
Wheeeww.
Thanx again guys.
P.S. I'm told that 0.0L means overload or infinite resistance on the meter being used.
Almost sounds like your not getting power in.
hard to believe the AIU is broken
Please disregard if this has been mentioned before
clem
Almost sounds like your not getting power in.
hard to believe the AIU is broken
Please disregard if this has been mentioned before
clem
Clem,
I pulled the connections at the AIU and the leads do have power because I can touch wires and get the switches to fire, so power is making it to the AIU, but from there who knows 
OK, so I did what Barry asked again... no joy.
Completely reset the system... no joy.
Pulled the AIU out and set it up with a different TIU and a test switch... no joy.
The AIU is toast. With a FasTrack turnout hooked to SW1, the straight does not click, the switched does click, the turnout does nothing.
C'est La Vie.
Cheryl,
I have an extra AIU NIB, I will sell it to you cheap, I am now using command control FT swithces. Let me know if you want it.
PCRR/Dave
Cheryl,
I have an extra AIU NIB, I will sell it to you cheap, I am now using command control FT swithces. Let me know if you want it.
PCRR/Dave
Sure, email is in profile. Tks.
Cheryl,
AIU coming your way via UPS
PCRR/Dave
Thanks Dave!!! 
New AIU installed, everything working, until... I tried to upgrade TIUs, calling it a night at this point. Totally frustrated. But at least all the switches, switch. 
Thanks again Dave for coming to the rescue.
Charly, Want to send me the AIU and I will see if I can repair it? G
Charly, Want to send me the AIU and I will see if I can repair it? G
Dunno, think it's worth it? How much we talkin' here. Shipping obviously...
If the $ numbers don't work out with GGG and the AIU will become a doorstop or bookend, I'll pony up the $12.35 USPS Priority Mail Flat Rate Box rate to send it to me. This is a very curious problem and I'll volunteer to diagnose it and report back to this forum on what I find. If nothing this should egg G on...
I was going to say parts and shipping. G
I was going to say parts and shipping. G
MTH Authorized Service Center and Technician
Lionel Independent Repairs
Virginia Train Collectors Member
Sounds like a plan, I'll let you know when it ships, still have your address from the connector. Probably will be next week, if that's ok. Won't want to go more than $30 - $40 dollars in parts.
Thanks
No problem. G
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