Wiring a "running light" into the Fan circut ?

rooster · November 15, 2007, 04:41:56 PM

We have a 95 olds Cutlass FWD,57K miles and it has a 3.1 eng SFI. These engines have been known to have problems related Temp creeping up to the red light coming on while on long hills.

Before I start throwing money at this thing I would like to do afew things, first being a "fan is running light"how would I wire something like this up, what kind of bulb?

The other thing I would like to do is a after market temp guage under the dash, I havent looked yet for a port in the block to do this yet, but there is probely a place.

Some of the cause's I have read about are:

cloged raditor int & ext
temp sensor
intake gasket
head gasket
waterpump
waterpump impeller
belt slip
grounds
thurmostat
computer
anti-freeze
fan relay
Draging AC clutch or compressor

The only thing I have done so far is replace the temp sensor 3 months when it was hot outside.

enjenjo · November 15, 2007, 06:25:53 PM

You will need a minature socket available at most parts stores, set up for two wires, power and ground. You can tap off fan power at the fan for one side, and ground the other side. the light will come on when the fan is running, and won't draw enough power to cause problems.

You may, or may not find a place to install an aftermarket temp sender, you may have to tee one of the hoses to set it up. Don't be shocked at the temp it is running, most of them run over 200 degrees all the time.

tomslik · November 15, 2007, 07:45:29 PM

you'll find the fan comes on at 226 degrees (normally), i forget what the temp is when it goes off.
one more thing, some fan setups have 2 speeds, some 3, others just one...
i see more intake gaskets leaking coolant more than just overheating...

wayne petty · November 15, 2007, 09:15:19 PM

this is an image of the cooling fan circut. i think you can click to enlarge it...

hook the light up to the light blue wire on the behind the radiator cooling fan... you need to make sure that both electric fans are working... looks like a pusher and a puller...from the diagram... the other side of the light to ground...

try not to test the relay wiring with a test light.. the ecm control circut will burn out at 1 amp of draw... teh big wires are teh fan and power supply.. you can jump those with a jumper wire...just for testing..

the relays can in most cases be opened to
inspect the contacts.. i open a white towell.. pull the spring off the top of the relay and work the contact arm out to clean and burnish the contacts.(on relays with a braided contact lead to the contact lever). on some relays. others are not cleanable..
except with dental tools...

relays have silver contacts.. ignitions have hard faced contacts.. silver is burnishable to restore the current flow.

on some cars there is a flexable filler section behind the grill and the core support.. usually held on with push type retainers..

this rubber device keeps the ram air flowing through the radiator and condencer at speed... without it the car may overheat at speed..

also change the thermostat.. someone may have modified it or it might just be open..

cars with electric cooling fans need a thermostat..

theory .. it works..

the coolant flows from the water pump back through the block . up the back of the block, forward through the head, and then into the forward coolant crossover or area where the thermosatat is.. there is also a bypass circut to allow a small amount of coolant to recirculate back into the waterpump and then through the block and head again... the closed stat keeps the coolint circulating inside the motor.. when the coolant reaches operating temp the hot circulation past the bottom of the stat causes it to open a bit.. the coolant is then forced out allowing the water pump to bring in cooler coolant from the radiator... the cooler coolant closes the stat allowing the hot coolant in the radiator to stop for the ram air or cooling fan airflow to cool it...

it the thermostat is locked open , removed, broken or whatever the water will circulate through the radiator and will go faster and faster as teh rpms increase.. never letting the coolant slow down to cool off...

try cooling hot soup in a spoon with your breath... .. and then try to cool it as it is being poured out of the ladle... same thing applys...

stats are under 10 bucks usually...

do not try to use a cooler stat with factory electric fans... 192/195F on domestic cars... the ecm control the relays to turn on the fans at a specified temp to control emissions.. and do to the fans turning with the ram air they wear out.(the brushes and bearings).. and the relays die also...

the fuel filter could also be restricted...
that will cause the engine to run lean and cause increased temps...

rooster · November 15, 2007, 10:53:38 PM

some where I have one of those small lights you install inside a cluster for turn signals, I guess that would be ok , I think that draw would be not much. I guess there should be a fuse in the line also!

Before I do any changing parts I want these reading's. Dont know much about car computer's , From what I can tell our 95 take a scanner to get the troble codes, paper clip trick wont do it!

Sense we have two 95 cutless's with 3100's Ill do some comparing! One gets the red light sometimes the other dont. I think the fan come on late, or the guage is out of wack. Car never spits anything out we just get the red light.

Thanks guys for the input

FUEL FILTER thats a new one! The list grows.

wayne petty · November 15, 2007, 11:39:00 PM

this will get you trouble codes.. for cheep...

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46030

but not data... it will also clear the codes, after it reads the codes 3 times.. Warning this will erase the learned memory.. and thr car will fail a smog test in some states..until the perameters have been met.. a few days to several months depending on how you drive... more than most people need to know...

csk sells a 199 to 229 buck real scanner from equus model 3120 that should cover all the computerised domestic cars that have an diagnostic connector and all obdII cars ...... it is the price of several professional scans at a shop...

most cars started being able to transmit data about 1982 or so.. some are more work to get to it..

i actually went into a kragen 3 weeks ago and chatted with manager as he was running out .. the last counter guy ignored me for 15 minutes .. helping people that walked up behind me... how did he know that i did not need to spend 200 bucks that day... maybe i call his manager and complement him ... .. he did seem to know exactally what he was doing... ...

rooster · November 16, 2007, 09:48:42 PM

I installed the running light tonight, it came on and off with the fan cycling! When the fan cycle shut down the light dimed as the fan blade coasted to a stop, I dont know if this would effect the life of the bulb or not, the bulb is 12V 2 watts.

Still looking for a place to hook up the sending unit for the temp guage, instructions say not to tee it. Have to do some more looking around on the net.

wayne petty · November 16, 2007, 10:09:06 PM

you can put somethig like this in one of the heater hoses...

this one was made up of dorman 5/8 hose barb by 3/8 pipe fittings and a 3/8 hose barb by 3/8 inch pipe fitting. to replace a little black plastic tee that kept breaking... always a long way from anywere...

unhook one of your heater hoses and install a short piece of hose to reconnect this tee to the outlet.. you get your choise of a side connect or an end connect which ever is easier...

it all depends on what size your temp gauge adaptor fitting is... 3/8 or 1/2 inch pipe.. i did have to go to 3 differnt stores to get all the pieces..

PeterR · November 17, 2007, 08:07:14 AM

Quote from: "rooster"I installed the running light tonight, it came on and off with the fan cycling! When the fan cycle shut down the light dimed as the fan blade coasted to a stop, I dont know if this would effect the life of the bulb or not, the bulb is 12V 2 watts.

After the power is cut to an electric motor, the motor becomes a generator while coasting to a stop. It is of no importance in your application but has been the cause of a lot of head scratching in situations where fans are wired to the ignition and the engine continues to run after the ignition is switched off.

QuoteStill looking for a place to hook up the sending unit for the temp guage, instructions say not to tee it. Have to do some more looking around on the net.

For accurate results a temp sender should be mounted in a way that it does not sit in the "dead water" as occurs in a normal T. There are mounts specifically designed to avoid the problem.

This shows a good picture of the item.
http://autometer.com/cat_accessoriesdetail.aspx?vid=52

Here is one for a radiator hose.
http://store.summitracing.com/egnsearch.asp?N=700+115+318084&D=318084

here is one for a heater hose.
http://store.summitracing.com/egnsearch.asp?N=700+115+320936&D=320936

Bugpac · November 17, 2007, 08:28:02 AM

replace the thermo switch for the fan, summit and jegs has them, get it to come on sooner, 226 is way to hot IMO, yes its factory, but maybe thats the leading cause of intake gasket failure, i would get a on 200 off 180...or so on...you will have to rewire the thermo switch plug tho....

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D890018&N=700+4294924500+4294839058+4294815584+115&autoview=sku

rooster · November 17, 2007, 10:05:10 AM

Quote from: PeterR
QuoteStill looking for a place to hook up the sending unit for the temp guage, instructions say not to tee it. Have to do some more looking around on the net.
For accurate results a temp sender should be mounted in a way that it does not sit in the "dead water" as occurs in a normal T. There are mounts specifically designed to avoid the problem.

I think I would have to use to heater hose type . This FWD arrangement of the cooling system has me a screwed up, water pump sucks from the bottom hose, and the T- stat is on the other side of engine. I think the line for the heater or between the pump and the t-stat and that coolant flows all the time in those lines. I really dont know! My hope's is that there is a port unknown to me at this time. I will probley do Wayne's design, about the same thing as aftermarket, save some bucks. Sense this setup is only tempory would proble use galvinised for the tee, that is if I dont find a port to fill.

Thanks

Bugpac:
You might be right! I just donk like the idea of going that route yet. The 95 is unmolested! The only thing I have done so far is the sensor. There has to be a reason this is happening, with the guage and running light my hopes are to eliminate possible causes one at a time by testing. Auto fourms are full of this exact problem on 3.1 and 3.8 GM engines. My guess is electrical grounds from ageing.

rooster · November 17, 2007, 10:07:00 AM

Quote from: PeterR
QuoteStill looking for a place to hook up the sending unit for the temp guage, instructions say not to tee it. Have to do some more looking around on the net.
For accurate results a temp sender should be mounted in a way that it does not sit in the "dead water" as occurs in a normal T. There are mounts specifically designed to avoid the problem.

I think I would have to use to heater hose type . This FWD arrangement of the cooling system has me a screwed up, water pump sucks from the bottom hose, and the T- stat is on the other side of engine. I think the line for the heater or between the pump and the t-stat and that coolant flows all the time in those lines. I really dont know! My hope's is that there is a port unknown to me at this time. I will probley do Wayne's design, about the same thing as aftermarket, save some bucks. Sense this setup is only tempory would proble use galvinised for the tee, that is if I dont find a port to fill.

Thanks

Bugpac:
You might be right! I just donk like the idea of going that route yet. The 95 is unmolested! The only thing I have done so far is the sensor. There has to be a reason this is happening, with the guage and running light my hopes are to eliminate possible causes one at a time by testing. Auto fourms are full of this exact problem on 3.1 and 3.8 GM engines. My guess is electrical grounds from ageing.

rooster · November 17, 2007, 11:56:18 AM

Quote from: "wayne petty"you can put somethig like this in one of the heater hoses...

this one was made up of dorman 5/8 hose barb by 3/8 pipe fittings and a 3/8 hose barb by 3/8 inch pipe fitting. to replace a little black plastic tee that kept breaking... always a long way from anywere...

Is this the tee you are refuring to?

Mine is metal, has a air blead screw in it.

HUMMMMMMMMM more possibilitys!

wayne petty · November 17, 2007, 01:55:40 PM

before this goes any further............

change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....

under 10 bucks......

one the engine temp has gotten to the red zone. the thermostat has been damaged.... it had been red lined.... extended beyond it working range....

the little wax pellet has expanded to its maximum and may have leaked past the seal or broken the rubber diaphram........

again.. it has to be a 192/195F stat on these gm cars...

stat $10..
engine $2,000 + towing+ inconvience of a dead car+

the only good thing that come from killing a motor do to a bad 10 buck part it the nice shine on ones shoes to to the kicking action of one upon his own pants seat....

and the new tag line...

It worked six months ago!!!!!!

wayne

rooster · November 17, 2007, 03:06:01 PM

Quote from: "wayne petty"before this goes any further............

change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....change the thermostat.....

under 10 bucks......

one the engine temp has gotten to the red zone. the thermostat has been damaged.... it had been red lined.... extended beyond it working range....

the little wax pellet has expanded to its maximum and may have leaked past the seal or broken the rubber diaphram........

again.. it has to be a 192/195F stat on these gm cars...

stat $10..
engine $2,000 + towing+ inconvience of a dead car+

the only good thing that come from killing a motor do to a bad 10 buck part it the nice shine on ones shoes to to the kicking action of one upon his own pants seat....

and the new tag line...

It worked six months ago!!!!!!

wayne

Change the T-stat , I got that!

That will be #2 on the list.
Number one is connect the sending unit of the temp gauge to record change's,.

The car has never overheated we have seen the red light several times though! The car is my wife's transportation to work its 1 1/2 miles to work! This time of the year the gauge stays just alittle over the center mark on the gauge, plobley wont be a problem until next summer. Now is the time to go after it.

Was that picture of the Tee you were talking about that breaks?