Hi Gary~

Did lights dim when it did try ?

Not sure what you mean by: "It is a Marine aire with IV controller. Electronic"

Typically Hatteras installed either Cruisair or Luneair…Luneair is long out of business…

Most all Hatt's came standard with A/C…Maybe yours was retrofitted in 98 ?

Marine Airrrr was another company but is now owned by the same company (Dometic corp) as Cruisair.

If it's Marine Air…Can you pick out the control in the below link ?

http://marine-ac.com/marine-ac…..ion-units/

Steve~

Pictures are always good, but right now I'm trying to determine if you may have burnt wire or connections…

If you get no amp surge, or voltage drop, then it's likely the issue.

But if you do see amp surge then we possibly have a compressor or capacitor problem.

Steve~

Post edited 8:44 am – May 13, 2011 by Steve Pooler

Mr. Dee said:

OK, I must be getting old lol…Me Too Gary… 

 

They are Lunaire units...That would mean they are likely original Hatteras equipment…Hatteras used Luneair equipment on the smaller than 50' boats during that time period.

 

The controller is the MTC-IV series 2 which looks like the XTC.…Maybe even closer to the the MTC-X (Roman numerical for 10) which is the next one down in that PDF, but if you notice dates…None go back as far as your 86 vintage which would be the 4th version…But no matter…Parts are not available for either.

 

The fan comes on and you can hear the relay but no change in amperage and the lights do not go DIM.…The relay click you hear may not be a relay…It's likely the reversing valve coil that usually energizes before a compressor start…The no amperage or lights dimming tells me it's not even trying to start.

 

Gary

Do the Cool or Heat indicator light/s light up ?…If so then we know the control is at least asking for the compressor to run.

First thing I would do is open up all electrical boxes (turn of breakers first of course)…Lunair units usually had a stainless steel box mounted on top of the unit in the engine room…If memory serves…There should actually be 2 boxes…The one for the unit (that has the capacitors in it) will be stainless steel…The other is made of aluminum, and will house the main circuit board for the control….

Check for burnt connections or smell….

if you smell something in the Stainless box…Look at the connections to the Run capacitor (small silver soda can like)

Again if memory serves….You may need to remove a rubber boot that the wires run thru to get to the connections on the Run capacitor…But it's a common place for them to fail….

Get back to be with your findings…Don't forget to check for the Cool/Heat light first…If it's not lighting, then the above may not be the issue.

Steve~ 

Post edited 10:19 am – May 13, 2011 by Steve Pooler

I believe the gated compressor wire will either be purple, or have piece of purple tape around the terminal strip end close to the connector…Measure from that to Line 2 (black/red)

But again memory  

Yes it could be a Triac but in your case (read your HOF post) where you had blocked or reduced water flow (which would cause high amperage draw) They usually fail in the Gated/Closed mode….Compressor would not shut off….

Steve~

Post edited 11:30 am – May 13, 2011 by Steve Pooler

Yep….Sounds like a wire was hanging on by a strand or two…

You can also check under the compressor's connection cover…There should be a small (diameter of maybe a quarter) black round thermal overload that may have gone bad…Jump it out for the test, but do not run the unit for very long without it (or a replacement) as it's the compressor's last line of protection…

Steve~