Charger converter fan not stopping

[Jukeboxfun]

Ok, I think I have determined why the converter fan was not stopping.

My fridge fan very rarely stops due to the low threshold temp on the thermo switch to start and stop it.

My current setup has two silenz fans, a 46 cfm and a 76 cfm running together. I started thinking the 12v draw from those might be causing the converter to run hot and thus the non-stop converter fan. As an experiment, I disconnected the 76 cfm fan and just let the 46 cfm run alone. Voila! after about 15 minutes the converter fan stopped and never came on again.

[AtomicNo13]

I really doubt a muffin fan posed much of a load on the converter.... What do they draw, like maybe 1 watt?
Typically there is a thermistor on the board that senses internal case temp. Are you sure the insides aren't fouled with fuzz, hair or other gunk?

[Jukeboxfun]

Originally Posted by AtomicNo13

I really doubt a muffin fan posed much of a load on the converter.... What do they draw, like maybe 1 watt?
Typically there is a thermistor on the board that senses internal case temp. Are you sure the insides aren't fouled with fuzz, hair or other gunk?

We have a dog, so that is possible. However, we have not been out that many times for it to be clogged. I vacuumed the louvers of the converter to be sure.

If the converter fan stops running constanly (which it did) I will only run the 46 cfm fan.

[AtomicNo13]

Have you checked the voltage output with a DMV? If its much higher than 13 and change volts then its working hard.
Try a canned air product to blow out the guts!

[AtomicNo13]

Originally Posted by AtomicNo13

Have you checked the voltage output with a DMV? If its much higher than 13 and change volts then its working hard.
Try a canned air product to blow out the guts!

Should read DVM!

[Rich Jenkins]

Right, so today's issue is the same as the OP. My converter fan will not stop running.

Coach is a '16 27' FC FB.

Both batteries are full of water, connections clean and tight, and I read 12.5V across them at the battery box.

We are hooked up to good 50A power.

If I switch into USE at the BD switch, I get 12.3 at the coach battery read out. All is well. DC circuits are good (lights etc. )

If I switch to STORE in this condition, the red LED in the BD switch goes dim, lights go dim. Last night in this condition, I got 9.3V on the coach readout.

The fan in the converter ran all night. I can switch the converter 20A breaker #1 off, and it will stop. It resumes when the breaker is switched back.

This morning I checked all the 12VDC circuit screw lugs in the converter compartment were tight. I found one screw lug loose on the floor of the cabinet. It looks like it came from one of the spare lugs.

Any thoughts on troubleshooting this further? I'm a good way from an Airstream dealer, on the road in Fort Stockton TX.

[alano]

So, if I understand correctly, you're saying that when you're connected to shore power, if you select the "Store" position, your battery monitor says 9.3 V and your lights go dim?

This points to a problem with your converter. By selecting the "Store" position, you are disconnecting your battery from the trailer's 12 V bus. When connected to shore power, your converter should be supplying 13.8 V DC to power the bus. Perhaps you can measure the output of the converter directly and confirm that you're not seeing 13.8 V DC.

[Rich Jenkins]

Originally Posted by alano

So, if I understand correctly, you're saying that when you're connected to shore power, if you select the "Store" position, your battery monitor says 9.3 V and your lights go dim?

This points to a problem with your converter. By selecting the "Store" position, you are disconnecting your battery from the trailer's 12 V bus. When connected to shore power, your converter should be supplying 13.8 V DC to power the bus. Perhaps you can measure the output of the converter directly and confirm that you're not seeing 13.8 V DC.

Yep. Exactly. Which is also contrary to the manual, in that it says without a battery, even, I ought to see charging voltage on the 12V side from the inverter/converter. Which I thought was kinda odd to see 9V.

UPDATE: I switched breaker 1 off, and the fan stopped. While doing this, I snugged down all the lugs from #1 to #8 on the 12V rail. I also rewickered the wires a bit, gently coaxing them all into a better area below the buss.

When I switched the breaker on, the fan did not resume. I saw 13.3 on the readout, then, 10 minutes later, 13.5.

Hmmmmm....

[alano]

Sounds like you addressed the issue - a poor connection. Saved yourself a trip to the dealer to boot. You're now officially knighted to address each and every problem that arises! Good luck with your new trailer.

[Rich Jenkins]

Originally Posted by alano

Sounds like you addressed the issue - a poor connection. Saved yourself a trip to the dealer to boot. You're now officially knighted to address each and every problem that arises! Good luck with your new trailer.

Lol and thanks.

As a retired engineer, unresolved gremlins in the electrical system are a bit worrisome. My wife said "Great! It's fixed." She's going to fix me an adult beverage later; so all will be well.

Rich

[alano]

What they didn't tell you when shopping for a trailer is that you need to become an auto mechanic, electrician, plumber, carpenter, audio/tv specialist, IT manager, and AC/heating specialist. Fortunately, I leave the chef responsibilities to my wife.

[Rich Jenkins]

Ok, so on arrival yesterday here in Las Cruces, problem recurred. I connected 50A service, all was well, had 13.7V on the readout in USE position. Turned to STORE, got 9.3V. Back to USE, had 12.5V, and the I/C fan started.

Hm.

Opened up the inverter/converter cover, turned off breaker #1, and again, snugged down all 8 DC buss lugs, rather more enthusiastically this time.

After this, I switched on the I/C, and the fan did not restart. In USE position, I got 13.7V. Then, in STORE, I got 13.7V. Yippee!

It has been in STORE the last 24 hours, and I've still got 13.7V, and NO FAN.

Current best guess is I10 West from Fort Stockton to Las Cruces (parts of that road were pretty rough) shook one of the connections again.

Anyway, things are running well.

[dkottum]

You may have fixed the problem if it was a loose lug. Low voltage systems need snug connections or you're likely to have a voltage drop. Keep an eye on it.