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Topic: HWH dead short (Read 920 times) previous topic - next topic

HWH dead short

Have been working in dash and under front of coach must have knock a wire loose somewhere. Tried another fuse with dash up since I did not know exactly when or why the original fuse failed. Hit the power button and saw new fuse blow immediately. Any usual suspects? Let the fun begin.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #1 –
What fuse is blowing?

Only with ignition on or ?
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH dead short

Reply #2 –
10 amp labeled HWH,  mine is powered thru the solenoid with key on, just verified. Tried to remove the control panel inside the coach but stuck pretty good.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #3 –
I would take apart and clean all connections at the HWH pump/reservoir.  Those connections are a lot more in "harm's way" than the ones under the dash. 
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH dead short

Reply #4 –
Btw it's in my driveway, will check below. Is there supposed to be a cover over all those connection s by the manifold?
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #5 –
Wire to master solenoid good
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #6 –
Quote from: wolfe10 –
I would take apart and clean all connections at the HWH pump/reservoir.  Those connections are a lot more in "harm's way" than the ones under the dash. 
Why would that blow a fuse?
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #7 –
Quote from: Old phart phred –
Why would that blow a fuse?

Lots more exposed metal (read GROUND) under there if a connection does pull loose or if a hot wire has been rubbed through the insulation and is touching meta/ground.

And, if there is water in a connection that has both ground and hot in the same pigtail, it could cause a short with water acting as the conductor.

No, not a 100% guarantee. Just where I would start. At worst, there is a few minutes invested and you know that part of the system is good to go.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH dead short

Reply #8 –
Fuse blows as soon as the ignition is turned to the on position and the hwh switch is dead center. Fubar the secondary solenoid trying to loosen and clean the connections, as the stud spun. Sbc-4201c solenoid appears to be fairly common continuous 100 amp unit. Getting 23 ohms downstream of the fuse to ground, and jumps to 54 ohms with  key in the on position. no voltage present downstream of the fuse in either switch position. Got me baffled unless a relay is grounding out on the application of power.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #9 –
Where on the dash is the hwh master warning light? I am finding out 4 binders of documentation has lost many pages appearantly. Wires behind the dash are bundled so tight with cable ties I probably pulled something loose while replacing the headlamp switch or air pressure guage. Thanks
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #10 –
Can't get the control panel out, removed control panel fuse, and today have no resistance to ground at all.  So dead short before panel I think. Has anybody removed there control panel?
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: HWH dead short

Reply #11 –
Sounds like a short in the short power up wire in the dash. The motor/ pack wires dont get power until the system is turned on. ,
 Maybe unhook the power wire at the HWH switch  and see if it drops short ,and run another wire.