Quote:
Originally Posted by javelin
So some progress as you seem to have proven your use/store is providing power to the latching coil OK (I assume you are testing the relay near the converter). A 1 volt drop along the coil feeder wires from the use/store switch/coach batteries seems a lot (since I don’t think the latch relay coil would use that much current, but don’t know its spec). The fact that your measured voltage at the coil terminal is still higher than Intellitec minimum voltage spec, means it should have operated and released the latching relay being tested (if the latch relay was functional). I am assuming all good grounds too not just good + volts.
It is not unusual that newer electronic controlled battery chargers don’t turn on (output) without some sense voltage coming from a discharged battery being connected to their output terminals, so the other option is a good car battery and booster cables (carefully not shorting clips together if/when using or you will be welding instead of testing).....or a 12volt DC power supply that can supply a couple amps of current. I would test a latching relay out of the coach with this method since you have less risk of shorting something (more connection control). Also don’t leave the battery connected to the relay coil terminals for a long time as they are made to be energized and then de-energized (simulate the use/store switch). I assume the coil contacts have an external series fuse that you connect to for protection.
The other option (I would try this, but do so at your own risk as I don’t know your coach and am only going from your descriptions) is to use one battery boost cable and "carefully" connect it across the main lugs of the latching relay (the one near the converter - SHORE OFF initially to test). Basically this “should” simulate closing this relay and “should” connect the coach batteries +12.6 terminal to the converter + output and DC fuse panel and you should see your coach DC lights etc come on now running off the coach batteries. The 50 amp cct breaker in series with the coach batteries that you found earlier should not trip if all is normal. If this does not do it (assuming no other open breakers or bad grounds or loose connections)....then I would be scratching my head now too. Remote diagnosis can be risky and I don’t want to cause you or you coach any damage. Sometimes we may need a tech familiar with your coach on site to resolve a stubborn problem. I am still surprised the Thor schematic for your coach did not show the latch relay behind your converter....what else did they not show?
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UPDATE:
Thanks for the lengthy summary! Yes, your last comment has me scratching my head as well...I completely removed the latch relay inside the converter cabinet. Of course, it failed bench test. I used a couple alligator clipped wires and hooked directly to the coach batteries while connecting the red lead to one of the small lugs on the latching relay, and bumping the other with the ground wire. The latching relay was DOA. Of course, I should have known this given the previous photo of it that I took, but a close up is attached. It clearly got "hot."
So now, with a new latching relay installed, here is the outcome: When bumping the Use/Store switch in either direction, I can hear the converter cabinet latching relay clipping. This seems to be working now that I've replaced the latching relay. HOWEVER, with the step light switch turned on, I can see the light momentarily illuminate when I bump the switch in either direction. It should power off in the "Store" direction, I suspect. At any rate, there is no full time coach power, just momentary as I bump the Use/Store momentary switch. Now I'm wondering about the Transfer box switching...
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