I rebuilt my cooling system using a new radiator and fan switch, and got the radiator fan to work on my car for the first time. The new switch is wired with just plain insulated automotive wire crimped to female connectors (packaging labels them "disconnectors"). Soon afterward, the fan ran intermittently in traffic. It turned out one of the connectors that plugs into the switch had loosened up somehow. The gap between the back "plate" and two "teeth" of the connector on either side had expanded. So I replaced the connector and it ran perfectly. For a few trips. Then here we go again. The fan doesn't come on in traffic. I could be imagining it due to recency bias, but it seems like the new connection has just a tiny bit of side-to-side wiggle room that I don't believe was there before. I tested the circuit by jumping the switch, and the fan runs. I tested the switch in boiling water with a thermometer and multimeter, and got continuity at exactly the temperature my switch is rated for. My guess is due to the heat going on down there, the connector may be expanding and loosening up? I recall the original radiator had a black plug over the wires. I thought this was to keep fluids out, but it may have been for thermal insulation. Is there some way around this? Maybe a spring-loaded clamping connector? I'm not above soldering!
I would have used a similar insulated plug as was originally there, but I couldn't find the part and someone told me to just wire it up. Seems to be just this very simple connection that keeps failing.
Has anyone else run into this problem? With or without dielectric grease didn't seem to matter.
