Erkan Hassan wrote :
>
> First, I am concerned that the weight of the fan being held in place
> against the radiator by the 4 plastic Ty rods will result in stressing
> and bending the fins. Is this a valid concern? Should I rest the fan
> on the lip in front of the radiator or on a piece of wood or
> something?
I asked the same question of my local radiator shop, they said the only
concern was to be sure that the plastic rods are not touching the tubes, but
are centered between the tubes. Otherwise they can rub holes. They also
cautioned to be sure there was some compression of the rubber pads, so the
fan cannot move against the core.
>
> Second, although I have a doctorate degree it is not in car
> mechanics nor electrical components. The wiring harness has 4 wires.
> One is the inline fuse to power the fan and hooks to the fan. The
> second is to vehicle ground.
>
> The third and fourth wires are stripped on the end and raise
> questions. The instructions say to attach the black wire "To ignition
> switch power flow only when key is on". The red wire is "To power
> flow even when key is off"
> 1. Does this make sense? It seems to me that if you are going to
> have power flow even when the key is off, this is all one would need,
> since the fan would work with the key on or off. Do I need power to
> the fan (and therefore the fan working) when the key is off? Since no
> further heat is being generated, won't things cool down by themselves?
> And even if they don't cool down by the time I am back in the car,
> driving again, the fan should kick back on with the key on. So do I
> connect both these wires to one site that works either with the key on
> or off?
I would assume this means there is a relay somewhere in your wiring harness.
The idea is to not have the fan motor current drawn through the ignition
switch (and possibly overload it). Based on my experience, this is an
excellent idea ! So, the wire to switched power would power only the relay
coil (maybe .2 amps), while the wire to unswitched power carries the current
to the fan motor (8-15 amps). (Note that the fan motor draws much more
current when starting than when running. The wiring, etc. needs to be able
to handle the startup current, at least momentarily.) The relay also
prevents another problem, where the spinning fan can feed enough power back
into the ignition circuit to keep the engine running for several seconds
after the key is turned off.
> 2. Assuming I need both to different sources, where exactly do I
> splice these wires to? What have others done in the past?
Not sure where a good point is on a 3B. For pre-TS60000, the fuse block
makes a good point, as it will accept the extra wires and has both switched
and unswitched power available.
I created a new terminal in the output lead of the alternator, where all my
high current accessories tie in, including the unswitched power lead to the
fan relay. The switched power lead goes to the hot side of the starter
pushbutton.
> 3. How do I know BEFORE cutting into all these wires in the car
> which ones work with the car on and/or off?
I don't have the info handy, but there are standard wire colors for the
different circuits. Should be marked in your manual, or on the VTR web site
somewhere. I would also recommend buying one of the cheap DVMs (Digital
Volt Meter, although in reality they are Digital Multi-Meters) at Harbor
Freight. Although they certainly have their limitations, they are cheap
enough that anyone with a LBC should have one, and rugged enough to keep in
the boot or spare tire well. Frequently on sale for $10 or less.
Randall
59 TR3A TS39781LO
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