...and I got relays on my mind, yes I got relays on my mind

[Turbogus]

Edit: Got the switch wired in and as it turns out didn't need to be grounded to function, it was the inclusion of that diode. Apparently the circuit is grounded by the relay that this switch controls.

 

[Turbogus]

Well since I wanted to adapt some of the other relays for higher amps (40 amp, not like the graft I did for the 70 amp relay though). Upgrading from 16 to 12 gauge wire but since these connectors


were going back into the Ford PDB, I had very Limited space to get them into their nacelles.
Luckily NAPA had available what they call Parallel Connectors


..that slipped over the ends of the connectors nicely and using my trusty racheting crimpers


...I was able to get a nice clean crimp, ready for solder and fit into the PBD nacells with a perfect 'click' of the holdfast


Next step is to test all of the circuits and switches and then a road test.

 

[Turbogus]

Well nutz, the override switch was working (for test) until yesterday. Flipping the override switch and I hear the relay click but the fans don't spin, maybe it was a mistake to solder the wires directly to the switch. There's power to the switch, so going to trace from there tonight, unless I have a scheisse day like yesterday.

 

[csuengr]

Seems awfully complicated for just fans. Then again to hook up my Contour fans required splicing exactly three wires. The PDC that came with the engine already had relays and fuses and the fans are controlled by the ECU. I have the fans separate, as that was the way it was in the donor car. 6 half dozen the other. The relays aren't rated, nor are they the square type, but the fuses are 30A. The circuit on page one is way overkill. I also don't understand your use of a diode. Back EMF isn't an issue in these type of circuits.

My reason for electric fans. My engine has no provision for a mechanical fan. Doesn't even have a water pump pulley. But the good news is that the fans have no problem keeping the engine cool.

Oh, I also don't have an override switch. Not much water out here.

 

[Jimbos76cj]

Well since I wanted to adapt some of the other relays for higher amps (40 amp, not like the graft I did for the 70 amp relay though). Upgrading from 16 to 12 gauge wire but since these connectors


were going back into the Ford PDB, I had very Limited space to get them into their nacelles.
Luckily NAPA had available what they call Parallel Connectors


..that slipped over the ends of the connectors nicely and using my trusty racheting crimpers


...I was able to get a nice clean crimp, ready for solder and fit into the PBD nacells with a perfect 'click' of the holdfast


Next step is to test all of the circuits and switches and then a road test.

Just a heads up napa sells those terminals that you "fixed". Atleast they sell packard 59 "big blade" and packard 56 "small blade" terminals. Unless the ones your using are ford and a lot different. Looks like Packard to me.

I also just wired in a Taurus fan and used 85 amp constant relay for it.. No mess.. No wierd connections. Wires up like a solenoid. $40 of amazon.

 

[IOPort51]

If memory serves me right, and it does from time to time, there is a problem with having voltage hitting the relay contacts from both sides at once. something about welding them together. I usually use diode protected relays and as I think of it I don't think the ones I am using now are, have to give this some thought.

So , just to get this straight, It is less complicated to replace the engine and ignition system then it is to wire a couple of relays??

 

[csuengr]

The relays were the only easy part. But I have put in electric fans (only) and I did a much simpler setup. Plus I have never had relay contacts weld together. That and the OEM's don't use diodes. Now, if it were a transistor controlling the relay, that would be a different story. That is one of the reasons that ECU's sink instead of source.

 

[Turbogus]

Ultimately I wired these up per Mike (of Jeep-CJ Forus fame) that many, many folks have had sucess with;



Luckily I have this diagram on hand so I can refer to it when I start tracing the wiring.

 

[Turbogus]

Well, I felt those donkey ears spring up last night! Was tracing wires with my Ohm/Volt meters and going from power to the switch to the first bank of relays and checking each one for power in/out I found one that failed. Suspecting a blown relay due to jumping connectors with a test wire I inspected the wiring to that specific 'Override' circuit relay and I found the ground wire had been pulled from the ground bus I installed on the firewall. ~ DOI!

 

[csuengr]

Well I now understand what the silly diode is for. It's still complicated. I just use fan controllers, or the ECU, to determine when the fans run. That is what they are for. Turning off the fan/s for water crossings, to me, is just an affectation. If I ever submerge my fans, the fans are the last thing I am going to worry about. Yes they may touch the radiator, but they are not going to do any damage to it. Mechanical fans are much more of an issue, especially if no clutch is used. An electric fan will slow WAY down when it contacts water, where an mechanical fan won't or not as much. Those electric motors aren't that powerful.

Oh, relays will weld the contacts on closing ONLY. Even then it is a special situation where the contacts open and close again within ms.

 

[Turbogus]

"Silly" diode?
When I first wired up these fans, negrlecting the notes on that diagram I omitted that diode and they failed to function. The following day I soldered in that designated diode and, wha-la it works.