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Scratching my head on this

tommy64
Explorer
Explorer
I have a unusual problem it seems. when I have the air running in the "auto" position on thermostat, it works fine, that is until I switch on a overhead 12 volt light, then the air just kicks off. It will come back on in about 2-3 minutes even with the light or lights still on. I have checked the converter with my meter, reading is 13-13 1/2 on DC coming in from battery. 11 volts on all dc fuses. on the AC side of converter, reading is 119 at all breakers. Reading at any outlets are 119-120, Reading at a 12 volt overhead light with battery disconnected is 10 volts, and coach connected to AC. But with the stat set with the "on" mode I can turn on all lights without affecting the air conditioner. Of course in the "on" mode I am actually by-passing the stat, in this mode the fan runs all time but the unit will cycle on and off (just like they did before wall stats)I don't have the knowledge to check out the stat (Coleman mach 1) but it seems to me that it could be in the stat, enough voltage drop when a light turns on to kick the air off, of course after 2-3 minutes it comes back on. Any suggestions, advise or any ideas please? In all my 38 years of rving and 12 years of that fulltiming I have never heard or ran into this!!
12 REPLIES 12

enblethen
Nomad
Nomad
Thanks for the update!

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

tommy64
Explorer
Explorer
I had to replace the converter, that solved the problem

Fulltimers
Explorer
Explorer
haddy1 wrote:
Does that 12 volt overhead light happen to be fluorescent? I had one that had a bad filter (capacitor) that caused problems with my thermostat and tank monitors. If the overhead lights were on, all tanks would read full and the fan on the AC wouldn't turn off.
My Brother in law had a florescent light that would turn his microwave on and off.
Fulltimers
Fulltimers Weblog

2003 Rexhall Aerbus 3550BSL
W-22 Workhorse
2005 Saturn Vue (Mr. Toad)
3.5L V6 Automatic

haddy1
Explorer
Explorer
Does that 12 volt overhead light happen to be fluorescent? I had one that had a bad filter (capacitor) that caused problems with my thermostat and tank monitors. If the overhead lights were on, all tanks would read full and the fan on the AC wouldn't turn off.
2019 Tiffin Phaeton 37BH
2018 Grand Cherokee Toad

enblethen
Nomad
Nomad
Did you verify that the converter is getting 120 volts AC input?
Did you verify that the converter has no 12 volts DC output?
Make and model of the converter?
make sure you get a multi-stage lower section replacement.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

tommy64
Explorer
Explorer
enblethen, now it makes sense, the converter is bad, going to replace the bottom part. thanks for the education

MrWizard
Moderator
Moderator
you are not the first

second thread in 30 days with the exact same problem
I can explain it to you.
But I Can Not understand it for you !

....

Connected using T-Mobile Home internet and Visible Phone service
1997 F53 Bounder 36s

enblethen
Nomad
Nomad
13 volts coming in and 11 volts on fuses doesn't make too much sense.
Are you using the same ground for readings?
Battery should go to the 12 volt DC distribution panel and the converter goes to the 12 volt DC panel.
Disconnect from shore power, then follow the 12 volts DC from the battery.
Or disconnect battery and follow 12 volts DC from the converter.
Cycling would indicate right off a 12 volt DC circuit breaker tripping and resetting.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

tommy64
Explorer
Explorer
thanks fellows for the suggestions. I will check the ground, Since I have over 13 volts coming in, then it is in the dc converter . will check the grounds again.

Ozlander
Explorer
Explorer
Could be a ground problem on the 12 v side.
Ozlander

06 Yukon XL
2001 Trail-Lite 7253

Ivylog
Explorer III
Explorer III
You have a 12V DC problem... you need the 13V you are reading on all fuses and lights, not 11. Once you solve the 12V problem your AC will work just fine.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45โ€™...

enblethen
Nomad
Nomad
You need to correct the 11 volts in the DC side. There must be a loose or corroded connection.
Thermostat in "ON" position only turns on the fan and not the compressor and fan.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker