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Where can I find a replacement resistor?



Jan 1, 1970
First of all let me say I am not an electrical engineer, nor do I even know
one. My electrical skills are very limited, usually to automotive
application, and changing light bulbs by myself. With that out of the way,
show some mercy if I ask a dumb question.

I have an old Recreational Vehicle Power Converter (DC Power Supply) in my
camper. It is a C Sinc. brand. It is a transformer type rather than the
newer type switching power supply. Input 120v/4.5 amps AC output
12.6v/30amps DC. This thing helps heat the camper in cool weather.

Over the years of intermittent use the connections on the resister have
rusted away, leaving nothing to attach the wires to. I believe that this is
called a "wirewound" resistor, It is a ceramic block 2½"X½"X½" with a wire
connection at each end. The lettering on is 4?(ohm) 10% 20W.

I have looked in the Radio Shack online catalog and on the
"" site and can't find any of this value.

Where can I find one of the correct value,? or, What can I substitute for
this value? or, Can I combine two of more resistors of lesser value

I am open to constructive suggestions.

Please reply to both the message board and by E-Mail, that way I will be
sure to see it. Thanks.

Jerry Greenberg

Jan 1, 1970
You will have to know the exact value. Resistors at 20 Watts 10% are
standard, but the value in omage must be known, or it is impossible to
have a resistor. the 4? means nothing. It can be 4.0, or 4.2 or 4.3,
or 4.7 ??? Or, is it 40, or 42, or 43, or 47, or 49, or whatever? !!!

Most any electronics parts distributor can supply 20 Watt resistors on
order if they do not have them. In some cases only a 25 Watt may be
available, but the higher the Wattage, the better, as long as it will
mechanicaly fit. There may be a minimum quantity order, depending on
the availabilty.

Jerry Greenberg


Jan 1, 1970
Use 4.7 OHM 25W 5% tolerance resistor , Radio shack P# 900-1291 $1.00
Ph 1 800 442 7221 will do the job if you don't have any other defective