Multiple Items, will be a long read... Alarm at 3;30AM, 2 Stage Fan Clutch, and other

ok, crap second time typing this... so here we go again... awoken at 3:30 by alarm... sounds like Polizei coming after me on the autobaun.... noticed a very faint version of this at 10 when we went to bed but could never locate so thought it was a coach or rv near us...nope, after 10 minutes of searching and another 10 of dismantling dash I found it. was just near the door hinge and thank gosh had a plug. fwiw, i did unplug the little black box and also the keyless entry brains thinking one or the other was turning it on, but neither had an effect... it was kinda cutting in and out a little cracking so I'm pretty sure something is failing but not sure what circuit or purpose this serves... not related to air pressure, tag or other chassis stuff, but did look like it was a prevost chassis plug and labeling... anyone know what this little gem is and what purpose it alerts us to?

next, With bad weather I got a weird Pro Driver Error, VSS Sensor issue... which with some research was kicking out the correct codes for Vehicle Speed Sensor.... was intermittent and seemed to come on after driving through snow and ice... I'm suspecting a connector somewhere... the dash speedo continued to work, but all other speed related functions such as cruise stopped working...it would clear upon turning coach on and off then was ok until bad weather again. Any wiring diagrams or schematics for the pro-driver unit, or this VSS sensor location and plugs would be helpful.

finally, I"m pretty sure my low speed fan relay isn't working... it's cold, and not florida cold lol... so this will have to wait until at least a 40 degree day, but any schematics of for fan clutch system would be great. It runs pretty consistent at 210 ish, and when it get to 220ish the fan kicks on and brings it back down to 200 ish... i removed the 190 thermostats and replaced with 175's which help but not enough.... also I can work around this by turning on the dash ac compressor switch, which cycles the rear compressor every once in a while which keeps it a little lower about 190 ish. On a hot summer day, when i run the dash AC it runs right at 175-180 so I know the ac compressor circuit it locked in much more for dash air.... any help here appreciated.

One more item, While running coach the coolant circulates from engine through aqua hot to heat water.. at faucet it appears to get hot.... the front and rear zones for the aqua hot heater though never really blow the heat like I would think they should.... it is pretty much just cold. When my webasto is firing right ( it is not again" it will heat it and work correctly, with plenty of heat coming from those small heat exchangers and the circulation pumps all work correct. wondering how these aqua hot heat exchangers are built? they don't seem to efficiently take the heat from the running coach which is 175 on the laser to the input side of the aqua hot and transfer it to the closed loop system of antifreeze in the fired heat exchanger and registers in the coach... anyone experience similar issues? dash heat will blast you out, but the rest of coach is forced to be running on ac rooftop heat strips to stay warm....

Would it be possible to get some info on your coach ? Converter, year, model posted would help. Likely another owner might have experienced this issue.
Just trying to help,
Thanks,
AL

Sure, I forgot that part... its and XL chassis, 1999 last of the rivets.... and a featherlite conversion... from what I have been told, this particular featherlite was build up in Oklahoma, and seems to be a bit of a one off coach...

thx

The alarm may be the engine bay fire alarm. If they get wet they give false alarms. The sensor is directly over the head of the engine.

Got to run, so I'll answer the other questions later, if no one else does.

I had accidentally left the driver rear bay open that houses the aquahot... maybe there is a detector there that got wet? it did rain that day.... drizzle anyway... the coach had been sitting for 3 days idle.... got me thinking there is a sensor in that bay?

Your fan clutch is always supplied 12V. It is activated by supplying a negative return. You may be able to provide a direct return at the fan clutch connector. If so, turn the key on, but don't start the engine. If you hand spin the fan and apply the return jumper you should see the fan slow down.

If you have a known good relay, break the coil tabs off. Pull the low speed fan relay. Again, ignition on, engine off. Inserting the broken tabbed relay should result in the fan slowing down. If this works, the problem is the relay. If it doesn't the return feed is not making it to the clutch or the clutch is bad.

The low speed relay is worked hard, so its failure after 15 or so years isn't a surprise. At less than $5 a relay, just replace all 3 fan relays.

12v and not 24? i'll guess these relays are in the back engine compartment connection box?

Okay, I'm going from memory. Don't hold me to the 12V. Yes, the relays are in the compartment above the engine. Hopefully, you still have the decal on the engine bay door with the relay identifiers and location.

Did you know you can get the wiring diagrams and air drawings off the Prevost site?

I didn't but i'll try to search for them... thx