Auxiliary fan resistor

[85MSteinway]

I finally found the source of why my fan wasn't working. At first I thought it was the resistor as I tested continuity up to the point of the 3 pin connector and it seemed fine. I had an extra resistor so swapped it and still didn't work. thats when I decided to test continuity on the 3 pin connector closest to the fan. My problem lied within the connector itself. Probably corroded or something loose inside. I rigged up a test solution to bypass the connector and everything works as it should. My question is can I just bypass the resistor itself and let the fan always come on in the high speed setting? Is there any reason I shouldn't do that?

In the 1985 ETM the hot wire from the high speed relay is claimed to be 4 (10 AWG) protected by a 30 amp fuse to the 3 pin connector. On the other side of the 3 pin connector its sized down to 2.5 (14 AWG) to the fan. I do have a 30 amp fuse in the box.

The wiring from the low speed relay is size 2.5 (14 AWG) protected by a 25 amp fuse run to the 3 pin connector. Its the wire size remains the same aft of the connector to the resistor and then joining up with the same wire that powers the fan from the high speed side of the equation. The fuse in my box is 25 amp.

I have serious doubts about the size wire claimed by the ETM. This is a Euro M635 car so maybe some things are different from the US CSI ETM? For starters the color of my low speed wire is different from the ETM. And the difference in thickness between the 2 hot wires seems too small. In fact, its hard to tell the difference looking at them and feeling them. I havn't cut them from the 3 pin connector yet so it might be more apparent looking at it dissected. But I'd wager its 14 AWG and 12 AWG if they aren't the same size. I would think the difference between 10 and 14 AWG would be obviously apparent. Maybe I'm wrong.

I'm no electrician. I'm confused why the high speed wire to the connector would be 10 AWG (claimed by the ETM) then drop to 14 after the connector to the fan. Wouldn't that defeat the purpose of having a thicker gauge wire up to the point of the connector? Or maybe because the run from the connector to the fan in the smaller 2.5 size is such a short run it doesn't matter? I suppose I can try it and if the 25 amp fuse pops I know it was too much draw without the resistor? Any performance issues, in regards to cooling, why I wouldn't want the fan to only run in high speed regardless of which temperature switch activates it?

hopefully this all made some bit of sense to any that might have some answers.

Jay

[baders]

Jay it won't make any difference running the fan in hi speed only. Perhaps noisier if anything. If you're in doubt regarding wire sizing, just go with the 10 AWG.