How do I install switch to turn on Cooling Fans

[Rolm]

How do I install switch to turn on Cooling Fans

My 99 3.8 engine still runs very hot in stop and go traffic I know that the cooling fans are not coming on until the temp is between the mid point and the hot. I did change the cooling temp switch with no change. I was thinking if I install a manual switch were I can turn on the cooling fans that should solve my problem. Question how can I install a manual switch to turn on those cooling fans

[panzer dragoon]

Look at the fans and see if they are 12V -if they are you need a 12V switch that can carry the current for both fans (12V, 2Amp (make the amperage about double what you actually need) etc).

If the fans are not 12V -you need to transform the voltage to what you need and then find a switch that is at least the voltage and amperage you need.

AC switches can work but the amperage is typically very low. =not useful.

You could use a 3way switch and have
#1 = one fan on
#2 (middle) off
#3 both on

[maxwedge]

This may not be a problem, the fans are programmed to turn on at 222 degrees, have you confirmed this operation?

[LittleHoov]

The fans kick on when the PCM sees a certain temperature and then grounds a certain wire coming from the fan relays.

You can manually ground this wire with a switch, but you have to figure out which one it is. This would require a Factory Service Manual specific to your year, either that or a lucky guess.

Also there are about 3 relays, and Im not sure which one controls which fan..so its a crapshoot without the right documentation.

Also, if the PCM sees the fans running when the temperature is too low, aka youve switched them on manually, it has been known to throw a code, which will illuminate your SES light.

[Rolm]

I was hopping that some has already done the manual switch solution. I did not want to mess around by grouding this wire and that wire just in case I blow something. I think I will visit the bone yard and look for a fan that will fit in front of the rad and tinker with that.

[Hoppy2]

Years ago I put an electric fan in my old 83 Merc Capri. Canadian tire back then in the early 90's sold a kit that had a sensor that mounted to the rad and a relay and wiring that hooked into the fan / power source to turn on the fan when required. You may check that out.

[LittleHoov]

Since you have the 3.8, you might consider this as a plug and play solution:

http://www.intense-racing.com/Mercha...roduct_Count=6

I DO NOT know if this will work with an Intrigue or not, Ive never seen an Intrigue with one. But the 98-99 Intrigue shouldnt be set up that much differently than the GP,Impala,Regal, etc of the same vintage, which that kit fits.

There are ways to do it manually. Im just not entirely sure how to do it, but its done quite often to H-bodies, and Im sure the W-body guys have done it elsewhere.

[Rolm]

Originally Posted by LittleHoov

Since you have the 3.8, you might consider this as a plug and play solution:

http://www.intense-racing.com/Mercha...roduct_Count=6

I DO NOT know if this will work with an Intrigue or not, Ive never seen an Intrigue with one. But the 98-99 Intrigue shouldnt be set up that much differently than the GP,Impala,Regal, etc of the same vintage, which that kit fits.

There are ways to do it manually. Im just not entirely sure how to do it, but its done quite often to H-bodies, and Im sure the W-body guys have done it elsewhere.

Thank you for the info, It seems a bit pricey but it sure looks like a nice pro solution.

[LittleHoov]

Yeah it is pretty expensive, several places sell them, so you may find one cheaper.

But like I said, I do not know if it will work with the Intrigue, and I dont think youll find a single site that will claim it will, nor will back you up if it doesnt, so there is a risk of it not working.

[Hoppy2]

Rolm,

If you are good at wiring yourself, you can probably just make a harness up yourself and save yourself $100. It looks like there are 3 standard automotive relays, I am not sure why because I thought there were only 2 fans on our intrigues, but anyway, you can pick them up and probably some wiring with the plugs on it from a wrecking yard. Go to radio shack and pick up a lighted switch if you wish and install it all in probably a half day or less.

I'm not sure if this will help you at all, but if you turn your AC on, the fans will come on as well. They come on because the condensor is mounted in front of the rad.

[Rolm]

I can't belive it I posted a wanted Ad in craigs list for the switch and a guy is willing to sell me one for $25 I will let you guys know how it is working. The down side my heater core blew for the 2 nd time

[Hoppy2]

Perhaps that is why the heater core blew, because of your excess heat. I know it has been hot around here the last few weeks, that and excessive Toronto heat and sitting in traffic could have possibly weakened your heater core. I don't blame you for installing the override switch.

By the way, I was looking at my intrigue the other day and why can't you just put a jumper switch to your fan relay to make it come on? Just go to Canadian tire and get a switch and some wire.

[Jimmy Olsen]

On some cars, turning on the A/C triggers the fans to come on at a lower temperature. I had a 1991 Dodge Spirit that would always run hot in stop and go city driving in the Summer unless the A/C was on.

[Jimmy Olsen]

You might want to get a grill thermostat and place it on the engine and see what temperature it reads when the fans turn on. Maybe the gauge on the dash is giving you a wrong reading.

[LittleHoov]

Originally Posted by Jimmy Olsen

You might want to get a grill thermostat and place it on the engine and see what temperature it reads when the fans turn on. Maybe the gauge on the dash is giving you a wrong reading.

A more accurate option would be to get a scantool and see what temperature the PCM is actually seeing from the sensor.