Is this a fan relay

[elkabong]

I bought an aux fan from ebay that came with a fan relay. I would like to confirm that it is a fan relay. I have looked up the part number on the net and I come up with ignition module.

It is a 1 inch cube with 5 terminals. Mfgr is Potter and Brumfield. The numbers are VF4-15F11-Z01 and underneath those numbers is 14100455.

I am interested in confirming that it is a fan relay and the connections for the terminals.

Thanks in advance.

 

[Dave L.]

GM part# for a cooling fan relay on a 1984 model is 14078902.

Dave

 

[JonM]

What you need is an AC-Delco 15-8218 That is for the main fan...I think that relay you have (which is a Delco 15-8426) is for a 94-95 instrument panal harness

Does it look like this?

http://198.208.187.182/servlet/com....gname=ACDELCO&prodlinecd=15&acpartnbr=15-8426

 

[elkabong]

Yep that it what it looks like.

 

[geekinavette]

Jim,

Yes that's a general-purpose automotive P&B 40 amp 12VDC relay. Here's a link to the datasheet: http://relays.tycoelectronics.com/datasheets/Automotive_Relays/VF4_DS.pdf

It'll work just dandy for a fan relay. If you want a diagram of how to hook it up just let me know.

Bill

 

[elkabong]

Bill - Thanks for the datasheet.

A diagram would be great.

Mounting the fan was not that bad. I can post pics if anyone is interested.

 

[geekinavette]

Yes Jim, please do!

 

[geekinavette]

Some relays have polarized coils, but I couldn't find anything in the datasheet that suggested that this one did. Look on the relay for + and - markings for the two coil leads, if there are none then it doesn't matter which coil leads the 12V and Temp Switch wires go to (ie either like the drawing shows, or swapped).

If it didn't come with one, I would strongly suggest that you use a connector, like they show in the datasheet, instead of individual wires to each terminal. That way if you ever have to disconnect it for whatever reason you won't have to fumble and remember which wire goes to which relay terminal. I think that's a common relay that parts stores carry, they might have the connector too.

 

[elkabong]

Bill - Thanks. The relay worked. As usual your prowess with things electrical has saved the day. For now I wired it directly to the main fan. It was 110+ Saturday and it was getting toasty in the garage.

The next series of images are how I mounted it. I used 1 inch x 1/8 inch aluminum for the top. For the bottom I used 3/4 inch square aluminum channel. I purchased at Home Depot - 3 ft. lengths about $9.00. The channel I cut three sides off of to make the tabs. Drilled a couple of holes and presto chango, mounting brackets.



Fan Mount Pic #1
Fan Mount Pic #2
Fan Mount Pic #3
Fan Mount Pic #4

 

[geekinavette]

Good deal Jim. Glad to hear you got it working.

I see what you did with the channel material. I love that stuff...I used the steel stuff to make the two AC brackets on mine (both of mine were broken).

Let us know how it works as far as cooling. I'm planning to add a pusher to mine sooner or later, or at least upgrade the stock puller to something a little beefier, that thing just doesn't flow enough air.

Bill

 

[elkabong]

The channel worked out great. I originally tried to bend the 1inch aluminum to what I needed but I do not have the tools. Hammer and vice was about it. For clarification I did not use the hammper on my Vette.

Today will be a good day. It is supposed to be 112*. Ick........ The last item is the stock alternator is marginal on handling the load. In traffic this moring the voltage level got down to 12.3 volts. Hence my other post about alternators.

I'll let you know how it cools later on today.

 

[elkabong]

This is how I am solving my power problems. I took the plunge.

http://www.alternatorparts.com/Double_Rectifier_cs144.htm

 

[elkabong]

Well here it goes - here is the update on cooling.

Did the additional fan make a difference in cooling - kind of. The temp runs at around 200* cruising down the road with the AC on and the outside temp is 105*-110*. I still have an issue with sitting in traffic - 225*+. I have also noticed that in the morning (outside temp 90*-95*) the temp hovers around 205*-210* in traffic which is acceptable. I have read other posts regarding the inability for the engine compartment to evacuate hot air and the temp in the engine compartment may be reducing the ability of the radiator to cool. Makes sense because my main issues are in traffic during the hottest point in the day - rush hour going home about 4 pm. Once I start rolling down the road at close to freeway speeds the temperature starts to drop. So it is one of two things - 1) The extra air passing through the radiator is helping with the cooling or 2) the hot air is finally being evacuated from the engine compartment.

I am still perplexed. I have a new radiator that has a core twice the size of the original and aluminum. New thermostat (180* - I am going to try a 160* for giggles). Coolant flows through the system, extra fan. Am I running up against a design issue with the Corvette because of its inability to adequately evacuate heat from the engine compartment? I live in an extreme climate where heat is concerned, so I may just be beating my head against the wall. But, this gives me something to think about none the less - an interesting problem to try to solve.

Does anyone know the differences in Corvettes that are sold in AZ? Other than the obvious - bigger radiator and aux fan.

 

[geekinavette]

Jim, you bring up a good point in evacuating air from the engine compartment. Ken73 and I had a discussion about that very thing not more than a week ago. I decided to try a little experiment with the manometer by just placing one side under the closed hood and venting to normal atm. pressure to see if there was a pressure differential between under the hood (I routed the manometer hose to just in front of the air cleaner housing). If in fact the air that the fan is drawing in is not able to escape, then there would be at least a slight difference in pressure between the underhood area and atm. The water in the manometer did not move the slightest amount the entire time my fan was running. Conclusion: There is not an issue with air being able to escape from the engine compartment.

The reason I think you're not seeing the improvement you would like is because your not shrouding the air from your aux. fan directly into the AC condensor, you're probably only getting a small percentage of the airflow from the aux. fan actually going through the condensor/radiator.

I've also noticed on mine that the bottom half of the stock fan shroud is open. I don't know if mine is missing something or what, but if that's the way it was from the factory then that's just lousy design....plain 'n simple.

We need to come up with some way to shround that aux. fan so as to direct as much airflow as possible through the condensor/radiator (I want to do this to mine also) and to improve the shrouding of the stock fan.

 

[elkabong]

Bill - Hmmmmmmmm

I need to think on the manometer thing a bit.

The shroud is interesting. I have the aux fan 2 inches from the AC condensor. I will admit that it was a guess on its position, but it is closer to the ac condensor than the main fan is to the radiator. Anyway, I tested by the air flow by turning on the fan (with the realy you graciously helped with ) and put my hand on the radiator side by the main fan and felt a pretty good amount of air. The air was dispersed but I figured this was because the air was traveling through the fin's and was being dispersed. So I called it good. Not scientific. The air from the aux fan (pusher) is fairly localized to the direction that it is pointed at on the ac condensor. What I am getting at in a long winded way is I don't know if a shroud would actually help because of localization of the air being pushed by the fan. hmmmmmm

My fan shroud is open on the bottom as well. When I purchased my Vette it was as stock as them come. I think it is supposed to be that way.

Here is another observation. I did this in my garage. Let the car idle with the hood closed. The fans turn on @ 195 and the temp will only go down to 183* (180*) thermostat. I have the low temp switch so the fan should turn off but it does not. I think this is the tolerances of the switch. Open the hood, the heat escapes and the temp goes down to 180*-ish and the fans turn off. So, the heat is being trapped inside the engine compartment. This would explain why when in traffic the temp goes up and when you start motoring down the road the heat is sucked out the bottom of the engine compartment and it gets cooler. I am going to throw in my 160* thermostat this weekend and repeat this. I expect my results will be that the fan will turn off and the temp will hover around 180*ish. There will not be any moving air because the car will be stationary. This should prove that the cooling system has the capacity to do its job adequately. This leaves us back to heat getting trapped (not air flow like with your manometer test) in the engine compartment and not allowing the radiator to do its job.

Heck, I may be all wet with this but it sure as hell is something interesting to think about. What do ya think - keep in mind that sometimes I can be as thick as a brick.

 

[geekinavette]

So it's not a matter of underhood air flow, but one of heat transfer. Ok, I can live with that.

I still think that shrouding that aux. fan and improving the shrouding around the stock fan will help.

 

[elkabong]

Yep - heat transfer.

I can fabricate a shroud out of sheet metal and give it a go. What the heck it can't get any worse. So you are thinking about something that just fits around the circumference of the fan and with a width larger than the fan blades?