No power to the chassis heater fuse

[dave001]

Hello all.. I've been trying to figure this out. Here's the MH:

1998 Daymon Daybreak 3270 on a 1998 Chevy P32 (P31872) forward control chassis.

My issue: No A/C - Heater at all from the chassis A/C controls.

So far, I've checked in the back of the in-dash controls and no power. I've then checked the heater fuse under the steering wheel and found that no power was getting to it (fuse is good), then to the 3 heater connectors/cables on top of the fuse and no luck.

That's about where my knowledge stops in terms of FC Chassis/MH and A/C.

I can't seem to figure out where to check next.

Can someone please help me and direct me to possibly where the issue would be and help troubleshoot it?

Thanks,
Dave

Update: I have power in the back of the in-dash control module. I've played with two brown and blue cables hooked to some relay/coil (# 1 on picture) underneat the A/C box under the hood. I believe I may have had some bad contacts and may have restored power or I'm turning real crazy . Unfortunately, the issue is still not 100% resolve, I now have power on the heater fuse and in the back of many of the connectors of the dash control module and even to the back of the fan switch.

One thing I've noticed, is in the back of the control module, there's a serie of little colored tubes and a white one going to a round shaped thingy (# 2 on picture) on the A/C box outside under the hood (sorry, I really have no ideas how it's called but will include a picture below). By touching it, I've noticed it was degrading and turning to powder.

What are those tubes for and could it affect my fan from not working and turning on?

Many thanks,
Dave

[DAN L]

imho that #2 thingy looks like a vacuum line.

[dave001]

Hello all, yup i've done some more research and this seems to be a vacuum actuator for the A/C. Only thing i can't figure out is if this only line could cause the whole system not to function, even in heat setting.. I'll keep on digging but it seems quite hard to find info as so far, from my understanding, the mechanical aspect of the A/C unit is made by the chassis mfg (chevy in my case) and the control unit in tye dash by the MH mfg (damon).. I'm new to this kind of older vacuum/mechanical control units and still trying to figure out how they operate and impact of an open line to the whole system..

Any input or direction on where to find more info on these systems would be appreciated.

Dave

[dave001]

Alrighty.. After beeing able to restore power to the control module + fuse, don't ask me how but I hope this won't become an intermittent problem and will instead stay as a one off user issue (if you know what I mean), I've checked the voltage at the fan and it's hot. I've unplugged the fan and tested it on a 12V direct source and it's just dead. I'll order a new one and will test further when received and installed. I'll also replace that white tiny vacuum hose going to the A/C actuator valve as I'm sure it'll solve another problem I had, which was either full A/C cold or full heater hot with no in between. Not that much of an issue since we're mainly using it during the hot season with full A/C on.

Oh well, I hope that'll be it after that..

Dave