Got this e-mailed to me from Willie and figured I would post it for anybody else with a single fan that would like to do this.
If you are unable to read or get this email me and i''ll send it to you. I tried to attach the file but i was unable to.
upshotunity@hotmail.com
1984 – 1992 GM F-Body Electric Coolant Fan
Specifications and Modifications
Single Fan Applications
1984 305 H.O. (L69)
1985 - 1992 V6
1985 – 1992 305 (LG4 & L03)
1985 - 1986 305 (LB9)
1987 – 1992 305 (LB9) & 350 (L98) without Factory A/C
NOTE
The wiring instructions for the Hayden 3652 and 3647 kits are independent of the
instructions for the manual turn-on switch. They do not interface with each other.
Wiring Instructions, Hayden 3652
Non-adjustable at 185 Degrees
The Hayden 3652 non-adjustable fan kit is designed to add a new standalone electric fan. We
will be wiring it to our existing GM fan circuitry. Therefore, it includes parts that are not needed.
Only one part will be used, the brass thermal switch. Of course you can use the entire kit and
wire it per Hayden's directions, but doing so requires completely discarding the original wiring
(design). This is not recommended.
Install the brass thermal switch per Hayden’s instructions. Locate your existing fan relay. It has
the following wires: 12-gauge orange, 12-gauge black/red, 18-gauge tan/white and an 18-gauge
green/white. Splice (tee) into the green/white wire with a new section of 18-gauge wire. Connect
the other end of this wire to either terminal on the Hayden brass switch. Connect the remaining
terminal to ground. The fan will still retain full factory function, but will also turn on at 185 degrees
(and off at 170), as long as the ignition switch is on.
Fan System Option
Please keep in mind that this additional switch is an option. It is not required. Without this switch,
the fan is regulated completely and no driver interaction is necessary. However, this switch is
required if both the factory and Hayden turn-on temperatures are needed. Examples of when this
switch is used: 1) Turned off on cold days which allows the engine to warm up more, and, 2) For
emissions testing. I call this switch “Auto”.
To install the “Auto” switch, simply add it in-line on the circuit described above, on either wire
connected to the Hayden thermal switch.
Wiring Instructions, Hayden 3647
Adjustable from 160 to 210 Degrees
In addition to the Hayden 3647 kit, an additional automotive 12-volt, 30-amp SPDT relay is
required. This relay will have the terminals labeled:
30,
85,
86,
87 & 87a, or
87 & 87.
Wire the Hayden unit as per instructions with one difference: Connect the Fan (+) wire to #86 on
the SPDT relay. The other relay connections are wired this way:
#85 to Ground (18-gauge), &
#87 to Ground (18-gauge).
Splice (tee) a new 18-gauge wire into the green/white wire at the existing fan relay and connect
this wire to #30 on the SPDT relay. Leave the center terminal on the SPDT (#87a OR a second
#87) unconnected.
Fan System Option
Please keep in mind that this additional switch is an option. It is not required. Without this switch,
the fan is regulated completely and no driver interaction is necessary. However, this switch is
required if both the factory and Hayden turn-on temperatures are needed. Examples of when this
switch is used: 1) Turned off on cold days which allows the engine to warm up more, and, 2) For
emissions testing. I call this switch “Auto”.
To install the “Auto” switch, simply add it in-line to the Hayden wire marked “ignition”.
NOTE
My design does not disable any of GM's circuitry. For 1988 – 1992, GM's
circuitry turns on the secondary fan on when you engage the A/C. For these
years, do not connect the Hayden A/C wire. The earlier years (1984 – 1987), the
secondary fan is controlled by a thermal switch located in the passenger cylinder
head only. For these years, connect the A/C engagement wire if fan operation is
desired with A/C on (highly recommended).
FAQ
Where did you add the in-line toggle? In the wire from the thermal switch? Or in the wire to the
fan motor? The toggle is in-line on the 18-gauge wire from the thermal switch. No, it is not on the
factory 12-gauge wire to the fan motor.
Do you think it is wise to wire the thermal switch directly to the battery (bypassing the ignition
switch)? Would this enable cooling with the ignition switch off? Wiring to a battery source can be
done. However in the summer, engine temps will run significantly higher than the Hayden
thermal switch setting (on at 185, off at 170). That means the fan will run for an extended period
after shutdown. Not recommended.
To augment the factory switch, you connected the positive fan wire to both the GM switch and the
Hayden? No. My design taps into the wire that energizes the factory fan relay. It is the lowcurrent
side of the factory relay. It does not tap into the direct current source for the fan (either
one). Notice my design does not tap into the 12-gauge wiring (except for the LED indicator), it
taps into the 18-gauge low current side of the factory wiring.
Manual Fan Turn-on
Locate the factory fan relay. It has the following wires: Orange, black/red, tan/white and
green/white. Splice (do not cut) into the green/white wire with a new section of 18-gauge wire. In
other words, “tee” into the existing green/white wire. Connect the new wire to a toggle switch.
Ground the other switch connector. The fan will now turn on with the switch as long as the
ignition switch is on. A lighted switch can be used, but it complicates the wiring slightly.
NOTE
If a lighted toggle switch is used, do NOT follow the wiring instructions supplied
with the switch. We are using it in a grounding circuit, not a power circuit (as the
instructions infer), so wiring will be different. Installation of this switch is not
recommended for the novice without a digital multi-meter.
“Fan On” LED
Splice (tee) a 22-gauge multi-stranded wire into the 12-gauge black/red wire at the existing fan
relay. Connect this wire to the positive lead on the LED and ground the other LED lead.
NOTE
If a 2.2-volt LED is used, a ¼-watt, 680-ohm resistor must be wired in series with
the LED (positive or negative side).
Thanx Willie |
