Gameshow Bob

Wow, my engine bay is so dirty, I'm embarassed to put this picture out on the interenet! Anyways, Is the little brass plug next to the thermostat housing the right place?


[Modified by Gameshow Bob, 3:48 PM 1/21/2002]

rainman69

AFAIK it is right. Now, I don't have elec fans, but I would assume that it would be a good place as it is in the same route as the thermostat and the heater supply hose. :smash:

Gameshow Bob

Also. . . What type of sealer do I need to put it in? Teflon tape?

1979toy

That spot didn't work on my '79. the rad. hose is directly over mine. I had to locate a thermostat housing that had threaded bosses for temp. switches. Most late 70's GM's have them. Grab the bolts too while you're at the used parts yard. I used thread tape on my switch with no problems.

Carl in LA

I use Flexilite fans right now and it comes with a bulb control that slips into the upper radiator hose at the radiator. You really have to clamp down on the hose/bulb to stop fluid from escaping when under pressure. I have been told of thermo switch setups that slip a metal sleeve into the (cut) upper radiator hose which is clamped off at each end... the sleeve has a bung which is threaded to receive the temp switch which is connected to the Bosch relay... which is then wired to the fans.

Paul L

The switch/sensor may already be there. It is on my 1979 although I do not have the auxiliary cooling fan option. Between the rear two spark plugs on the passenger side.

john73bb

I have heard (this has never happened to me) that using teflon tape can cause your sensor to not ground properly. My experience has always been that the threads cut through the tape and make contact. An easy way to tell is to measure the resistance between the housing of your temp sensor and the engine and make sure it is 0 (or whatever your meter says 0 is).

Gameshow Bob

I looked on the passenger side of the block btwn the #6 and #8 cylinder. There is a cap right there it seems. Also, this picture shows what looks to be a temp sensor as well between the #1 and #3 cylinders. Anyone know what its for? Choke?

Paul L

On the driver's side, that is your coolant temp sensor. On the passenger side I do not know what you mean by a "cap." If it is simply a plug of some kind, that is where the temp sensor for the fan goes.

Gameshow Bob

Doh! Nevermind. . . Found it in the Shop Manual

Paul L

You beat me to the punch!

Gameshow Bob

Yea, I mean a plug. It is an awkward place to put it the way I would like to route the wires, but it doesn't look like I have much of a choice.

Paul L

But you can get the proper wiring harness for it from sources such as: http://www.lectriclimited.com

Budman68

Gameshow Bob - I used a Haynes fan harness from O'Reilys. It comes with a sensor that pushes throught the radiator fins and a relay. I think it was about $20 large.

SteveG75

Spal recommends installing the temp switch in the cylinder head. Since I could not get the PITA plug to budge at all, I installed it in a therostat housing. Only problem so far is that the thermostat is a 180 and the fan switch is 195on/175 off so once it starts running, it usually won't shut off till the car is off. :smash: :smash:

Gameshow Bob

I have a good wiring harness and all of that. . . I was just planning on running all of the wires down the driver side of the engine compartment down to the fans. . . Looks like I'll just have to go across the cowl then down the passenger side and stop at the switch. Not that big of a deal as long as all of my wires are long enough. *fingers crossed*

1979toy

I expected the same problem with my 160 thermostat and 185 on, 170 off thermoswitch. I drilled two 1/4 inch holes in my thermostat and my fan now cycles on and off regularly.

KenSny

IMHO:

1. I wouldn't feel "safe" putting the fan contoller in the thermostat housing. Seems to me that could flucuate a lot depending on whether the thermostat was open or not.

2. The next best place would be in the intake manifold water passage opposite the heater hose fitting.

3. The best place would be in the passenger side head, same location as the temp gauge sender. This is where I'm going to install mine, a little more work - maybe. After all I want to control the engine temp so why not be sensing the coolent that's in the hottest section of the engine?

chadman

If the thermostat hasn't opened why would you want the fan running, the heated water wouldn't even be flowing yet? I have the spal setup and installed it in the therm housing after the thermostat. It works just fine, I would think you would want the thermostat to work before you start cooling the radiator. Ps you can by a housing at your local parts store, ie checker auto. Less than 10 bucks, and way easier than scrounging a junk yard. I think I bought one for a 1980 corvette.