Reply to "Diodes in cooling fan feeds"

I discovered the diode thing as I was removing accessories to pull the radiator to straighten out my valence.

After I got it out I just couldn't make sense of the wiring I found. The wire colors were right, but they seemed to terminate in the wrong spots and some appeared to be missing. Well, I found the missing wires, neatly taped up in the right headlight bucket area and I finally figured out what those two small studs are on the front right side of the reinforcement at the front of the trunk area. Thats where the fan relays are supposed to mount. I wondered why I couldn't find the darn things.

One of Miss P's priors, I'd guess while putting in the diodes, removed the relays and routed the fan wiring directly through the radiator thermostats! The fans never failed me (ignorance is bliss) but now that I know I cannot leave it this way.

I untaped all those other wires and there they all were, the blacks, the brown, the gray. Every wire necesary to match the wiring diagram.

So, I'm going to restore the relays, and follow Mikes Pantera Place cues and diagrams. I'll add one for my auxiliary third fan too. I think that going to the battery for fan power and keeping the load off the ammeter (mine's only a 50A VDO guage) and ignition switch is a good thing.

Now that I know about the voltage drop across the diodes maybe I should try to eliminate them.

How now to control the backfeeding/engine run-on thing? If I should try to shut down while the thermostats have pulled up the relays and are calling for fan, the current path is there for a backfeed and therefore run-on.

I'm afraid if I use a fan master switch like Marlin Jack, someday I'll forget to turn it on!