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Hayden 3652 not turning fan on?

11K views 6 replies 4 participants last post by  454headache 
#1 · (Edited)
Rewired my truck's taurus fan so that high speed would be automatically turned on by a Hayden 3652 thermo switch (see link below) as well as a manual override. The manual override switch works just fine, thank goodness. But the auto switch does not. Here's a description of how I have it wired-

Temp switch 2 terminal is connected to the 87a terminal on the relay. Temp switch C terminal is then connected to the low voltage + on the glow plug relay I'm using to turn on the fan.

Manual switch is connect at one end to Bat + and on the other to the relay. 87 terminal on the relay is connected to the low voltage + on the glow plug relay.

http://www.haydenauto.com/Upload/Ha...heets/12623-IS-3653-adjustable-thermostat.pdf
 
#2 ·
The Hayden kit uses a relay to switch the current for the fan motor. The temp. probe switches the relay.

The relay connection points 85& 86 are the coil of the relay. 85 is connected to ground. 86 is connected to the thermostatic sensor (TS).
The other wire of the TS is connected to 12 volts +.

The relay connection (common) point 30 is connected to 12 v +.
The relay connection (normally open) point 87 is connected to the fan motor.
The relay connection (normally closed) point 87a is not used in this application.

vicrod
 
#3 · (Edited)
Hmmm...

I have the relay set like this-

87- To Fan Motor
87a - Temp Sensor Switch
85- 12 V ACC ON
30- Manual Switch
86- Ground

I thought terminal 87a would be used to turn on the switch which would then in turn complete the circuit and turn on the fan when the temp was high enough. This is not making sense. The thermostatic switch just completes a circuit, like a manual switch. Thus when the manual switch is off, 87a should be closed and provide power to the temp switch and turn on the fan. What the fudge! :pain:

Oh, the 3653 does not need a relay to operate.
 
#4 · (Edited)
It just should not matter where the temp switch is wired in even, it could be on a ground, it's just a switch and all it should do is break a circuit or complete it. I suppose I'll put the temp switch on terminal 30. I'll wait until tomorrow so I can buy a circuit breaker and have two connections running off that instead of an ugly splice. Similar to this http://media.photobucket.com/image/...mp car DIAGRAM/Uff-da/HRBB/Rad-Fan-Wiring.jpg
 
#5 ·
The Bosch relay wiring info at the top of this thread should be helpful.
http://www.camaros.net/forums/showthread.php?t=111222

You need to have
87 - to fan
87a - unused
86 - to 12v through both the manual switch and the thermostatic switch
85 - ground
30 - constant 12 volts power

When 12 volts is applied to 86, either through the thermostatic switch or the manual switch, the relay will connect 87 to 30, and the fan will come on.

Bruce
 
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