Smoking wire on 420G

As I was attending to something in the engind bay, after a short drive with the AC running, I saw smoke in the liw, early morning sun.
It came frim the white wire attached to this odd part with 2 spring like components. Another 3-4 wires were also attached.
What part is this related to? I guess either AC or electric windiw regulators (as another G without these US market extras, doesn’t have it).
Cause and remedy???

My guess is resistor pack for the fan speeds! The coils get hot. Can smoke if oily. The wire shouldn’t melt, short to ground?

You can disconnect the wires and see what stops working when.

I recon it was just a bad contact. The rest of the wire looks fine. I would just replace the connector and everything should be fine.

Hi Peder,
Davidsxj6 is correct, that is the resistor for the A/C blower motors speeds. The coils will glow red when in use and there is a fair amount of current going through them at times.

Great info. Thanks.
I had the fans running with ignition on, and the contact back in place. The connector got very hot and I withdrew it. This caused the fans to lose a bit of speed.
I will just leave as is. Dont use the AC very often in Sweden.
Wonder what causes it to get hot and emit some smoke this morning…

Harry could be right. Can’t hurt to leave taped off if not.

Hi Peder,
I would guess that one of the coils broke and shorted to ground causing the wire to over heat and melt (smoke). The brown, white & blue wires go to the RH blower switch. The orange, green and red go to the LH blower switch.

I would not be inclined to do that…most vehicle fires are electrical !

In this case, often this is caused because the male/female spade terminal has a high resistance, due to corrosion or being loose

The last answer from Bob-S may also be correct

I changed the contact and pushed it well onto the male bit. The springs are not broken.
Turned the ignition on and turned on the AC fans. No smoke and not a very hot contact, but I could feel the springs getting hot. Perhaps they always get hot, but I have had no reason to put a finger anywhere near in the past.
So am I ok to leave this behind ne and usd the AC when I want??

I think yes! The springs have to get hot, they drop the voltage (due to their resistance) so the fans turn slower. They are probably bypassed on full fan speed. This is why they’re in the engine bay and exposed.

summary; sounds good…looks like the spade terminals had become corroded= hi resistance=high current

springs always get hot mate, just like a toaster, or boiling the jug

additional info;

the above situation caused me to install hidden relays for EACH speed (in another vehicle)

otherwise, when any part of the fan electrical system starts pulling too much current, it goes thru the ignition switch…and can burn it out

This happens eventually on an old car, the fan may stall for instance, and pull max current, or any high resistance in the circuit, if (and sometimes even if) the circuit is fused, wires switches and other things can burn up…and possibly even catch fire

Almost all newer vehicles I have examined are designed differently, so this is no longer an issue

I would take the time to clean all spade terminal connections in your car. If one fails, the others will soon follow. Just disconnect the battery first or fuses and other wires will smoke!


Make sure to put smoke back.