The blower resistors periodically fail in both my 96 and 99 Legacies.(I have the circuit if anybody wants it).

In most cases it is the soldered joint which melts, and only occasionally the coils break.

Why is there a piece of highly curved springy metal connected with a soldered joint to one of the resistors? The metal does not appear to be a bimetal strip. Is the melting-point of the solder being used as a first-line protection to save the coils?

If not, I intend to use higher-melting point solder or braze the joint?

Gil

The coil is a heat sink to help cool the resistors.

Yes but it isn't a coil it's a U-shaped strip of metal about an eighth inch wide and an inch circumference?

Can you take a picture of it?

Yes I have attached a picture of it. It is bronze color shaped like an inverted U. Thanks for your patience. Sorry pic is blurred I do not have the latest camera!

Gil

The blower resistors periodically fail in both my 96 and 99 Legacies.(I have the circuit if anybody wants it).

In most cases it is the soldered joint which melts, and only occasionally the coils break.

Why is there a piece of highly curved springy metal connected with a soldered joint to one of the resistors? The metal does not appear to be a bimetal strip. Is the melting-point of the solder being used as a first-line protection to save the coils?

If not, I intend to use higher-melting point solder or braze the joint?

Gil

Although circuit diagrams I have seen don't show it, a piece of metal such as you describe typically is used for thermal overload protection. If that's the case, a low melting-point solder would usually be used for one joint of the thermal protector; if the solder softens sufficiently due to excessive heat, the metal strip "springs " and breaks the electrical connection. It's possible that the same solder is used on all of the joints in the blower resistor assembly.

 

If you're experiencing regular failure of the resistors, the blower motors may be drawing too much current.

See http://www.endwrench.com/pdf/elec/MotorRepairsInfoSp01.pdf

 

Sometimes excessive current draw in DC motors having brushes and undercut commutators is due to conductive material (brush dust, etc.) stuck in the grooves between commutator segments; cleaning that out can often reduce the current to normal. I don't know if Subaru blower motors have undercut commutators, but if so and you suspect high current draw, it might be worthwhile to investigate that possibility.