Alcanboats Forum

Hi

I have an Alcan 40 which originally had Volvo 170s. I replaced them with Volvo 200s and all has worked fine. Recently we had a heat smell coming from the dash and on investigation I found that the smell was most likely from some original black tape which was sitting on a ballast resistor. The resistors measure 12.5 Ohm and are ceramic about 3 inches long.

I disconnected the hot lead from the one resistor and started the engine just fine???? Then I reconnected the resistor and restarted the engine to see how hot it got. It gets too hot to hold a finger to.

The output wire from the resistor to the wiring harness has a lable which says "attach to resistor unit on inst. panel" which must be original to the 170s.

Does anyone have any idea what these resistors are for"???????

Thanks

John BFB

Hi John,

These resistors are used to reduce the primary voltage at the points from 12V to about 6V. Why these were located in the instrument panel is a curiosity. My original instrument panels for the 170 engines had these same resistors at the panel. In the original design, the coils were fed 12V during cranking to provide the hottest possible spark to get the engine going. After disengaging the starter, the feed to the coils went through these resistors because 6V on the primary side of the coils was sufficient to keep the plugs firing, but reduced arcing and wear on the points.

Rob

Thanks Rob

I replaced the original 170s with Volvo 200D. These engines have a resistor at each coil. I wonder if I can remove the resistor under the dash. Guess I could disconnect them and monitor all of the systems. I hate the heat generated under the dash.


John