blove78634

Let me post my situation. I am currently in the ARMY stationed at Ft Stewart, GA. For the last 5 months I have been working at Walter Reed aiding the families and Soldiers that were injured in Iraq. I bought an 88 IROC on Ebay for 1600 bucks. Got a steal on it!!! Any way, I have taken the car to my home in GA for my 16 year old to drive until I get back.

My best friend (fairly knowledgeable about cars) who is stationed with me is helping me and my son out while I am in DC.

Here are my problems:

Cooling fan quit coming on. Actions taken: will come one with a/c on. checked the cable (radiator fan switch) itself by shorting it out and the fans come on again. Bought a new radiator fan switch, installed it and no dice.

Since the antifreeze came out when they pulled the switch, I had them change the top, bottom radiator hose, and put a thermo stat in since there wasn't one installed when they pulled the housing. They put in a 180 degree thermostat.

When they started the car it got up to 240 and no fans.

Should I have them replace the fan relay since the switch is new. Is it possible that there is air in the system and if so, how do I get rid of it.

I am including a pic of my steal. Any tips/advice will be appreciated.

JamesC

iTrader: (5)

I'd replace the relay. To rid possible air in the system, run the car at idle without the radiator cap for a while (may take a couple of times). Other cooling considerations: Did the lower replacement radiator hose have a spring inside to keep it from collapsing? Does the car have the lower air damn? Any crud between the condenser and radiator?

A bottle of Water Wetter might be of some help.

JamesC

blove78634

Ok, here's the deal. They changed the radiator fan switch, lower radiator hose (no spring, but not collapsing), upper radiator hose, thermostat, 50/50 coolant.

Thermostat is installed correctly, and works (checked in boiling water).

Car still gets up to 240+ and it is now overheating. Don't know if the head warped when it over heated last time, or not. It takes a good 15 minutes for the car to get to 240.

Any advice.

mylittlehoney

Seems like youve done quite a bit to keep it from over heating and still no cookie? Have you made SURE that the water pump is actually circulating. You can find this out by opening radiator while running(cold to be safe then let it heat up to get themostat to open). Find out for sure if its circulating.

blove78634

My partner said that when he looks in the radiator that the water is circulating. "Please keep in mind that my partner is taking care of my car in GA while I am in DC". He hasn't taken it on the road to see if it will over heat while driving. So we only know it does this while at idle.

There is an air dam underneath for when he does take it out.

So frustrating being 623 miles away, and can't see what is going on.
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another item to add is that it is only in the 80's. The real GA heat hasn't hit yet. Car just started this crap in the attempt to get the car back to the way it's suppose to be set up. I bought it off of Ebay and the two time that I have actually seen the car all we have done is fix the hack job the previous owner did to it.

JamesC

iTrader: (5)

[QUOTE=blove78634;3763473He hasn't taken it on the road to see if it will over heat while driving. So we only know it does this while at idle.[/QUOTE]

My bet is that it won't reach that temp going down the highway. Get some air in there and see what happens.

JamesC

blove78634

come to find out they didn't have the rad. cap on when running it. still trying to figure out the fan situation though.

ZZ28ZZ

You mentioned that you grounded the wire going to the temp switch and the fan came on. This indicates the wiring/relay/ fan are all ok. Was the new temp sender wrapped in teflon tape (on the threads) by chance? That could prevent it from getting a ground.

Having a good sealing radiator cap is critical. For each psi of pressure that builds up, the boiling point goes up 3 degs. 15 psi X 3 =45 +212= 257 degs!
Test or replace the cap.

tom86iroc

iTrader: (1)

did they replace the sensor in the pass head thats where the sensor is people get the temp gauge and temp fan turn on confused watch out cause the knmock sensor is on the same side that what it sounds like if one fan comes on with a/c like it should but the primary fan doesnt come on sounds like the switch ;0

abray1

The computer grounds the relay on the primary fan I think and the ac fan should come on when the ac is turned on. Take the radiator out and clean out all the crap that is stuffed between the radiator and condensor. I have to do that every year.

eeeeeefirebird

iTrader: (3)

grounds fuses and relays... my first thought wouldve been the temp switch. on the 2.8 i had, the fan grounded on the pass side where the air filter box was, with about three other wires on the same bolt, and the bolt was rusted out and there was just a bad connection.

blove78634

ZZ28ZZ, your the man. They sure did put thread tap on the threads. I am heading back to GA tonight to fix my car and a water heater. I will pull the switch and remove the thread tape.

Yes, they did change the radiator fan switch for sure and not the knock sensor. Thread tape makes sense now.

Thanks. Will post an update tomorrow.

blove78634

Made it to GA yesterday. I took the teflon tape off and before I put it back into the head, I took my heat gun (used in the old days when soldiers actually had to polish boots unlike todays Army). Sorry, plugged the fan switch in and when it was hot I grounded it to the headers and wollla, FAN POWER!! Don't get excited because I sure did. Put the damn switch back into the head filled it up with anti freeze and did all of that happy crap. Drove it all morning, never got to 220 (just under). Stopped to pick up my partner and she shot up just short of 240 and you guessed it no fan. SON OF A B*#ch. The only thing that I can think of is that there is corrosion in the threads. But why would it just stop. Remember, the old switch worked and then quit.

HELP A SOLDIER OUT HERE!!! I would like to figure this out before I retire on 30 September 2009. Yes Sir!!!!

ZZ28ZZ

If it's tight and tape was removed, it should make a good connection. Must have a intermittent connection somewhere. Ground the sensor wire so the fan runs and start wiggling the wiring and connections at relay, fan and sensor. Keep in mind the fan motor or relay may have an intermittent open circuit internally. A volt/ohm meter would come in handy.

tom86iroc

iTrader: (1)

check the fusible link by the battery mine wasn't melted all the way but it was broken internally so it wouldn't get power all the time

Drakon543

definitly sounds like a short somewhere i think i read that u said the old switch worked then quit and now its a new one and it still quit
sounds like u've chased every option down make sure u check all connections for stupid stuff like a bit of corrosive build up hehe lot of posts i dunno i might be repeating something already said

blove78634

I read all of the responses, and want to thank everyone. Had a honey do list waiting for my back side when I got home. Never figured it out (fan problem). Just running around town with an AC system on that don't work (but the fan comes on). When I head back next week I will try again. I am thinking of getting the aftermarket temp snesor and relay from Summit. Any input????? I do have a new post for electrical, but going to throw it in here. Tail lights just quit. Son went to a friends graduation and I watched him go down the street with them on and when he got to the grad. someone told him the tail lights quit. I am fairly knowledgeable with schematics (Tank Master Gunner). Anything from the cooling thread on tail lights before I post on electrical???

Thanks again.

ZZ28ZZ

Are the dash lights out too? They are on the same fuse. If the fuse is good, I'd start looking for broken wires under the dash. Some years had solid alum wiring to the tail lights and it would break easy, especially if you tried to splice in trailer lights. I know they used alum wire on 82 models, not sure abt later years.

FlyDoc

I am having the same problem with my 92 RS, the fan works with the A/C but not on its owen. I also have replaced the fan relay, fan swich, waterpump, uper and lwer radiador hoses, and thermistat. I have also spent time with the multi meater chasing the problem, The ony thing I can think of is the ECM is not functioning???

we can not be the only ones with this proplem.
what do you all think????

BluFBdy

iTrader: (1)

add me to the problem list, replaced fan relay, temp sensor( the one in the head, and also the one on the manifold) water pump, hoses, and everything, i got fed up and ordered a fan wiring rleay kit off jegs, on or off switch so i dont have to mess with it any more, my only issue is if i hook this up will it bypass the ac turning the fans on?

blove78634

When I was at home this weekend I made a stop into my friendly Advanced Auto. They had a kit in there for the same thing as the one from jegs (bypass the vehicle system) for $30 bucks. I read the back and it had ac fan relay's in it as well. here is the best part, only $40. However, if someone on this thread swears by the Jegs brand and paid 500 bucks then I am going to pay 500 bucks. I don't know about you but I hate being the guinea pig. I am giving people more time to respond to this before I actually order the one from Jegs.

Help!!!!!!!!!!!

blove78634

Drama continues. I bought a flexilite variable speed control, aftermarket temp sensor. Put the damn thing in and the control box was defective. Called flexilite and went through some trouble shooting with them for about 30 minutes. Needless to say the box is on it's way back to Summitt for an exchange.

I would love to see someone take a picture of a fusible link, so I know what the hell I am looking for.

Thanks

tom86iroc

iTrader: (1)

the fusible links run off the main battery wire usually are orange from the factory they have little pigtail conn. on them should be 1 or 2 of them at the battery good luck

dirtywhiteZ28

The only thing I haven't seen anybody mention checking in the previous posts is the oil switch. HUHHH???? Yea I belive if you look at the wiring diagram you will see it is also part of the fan circuit. Why GM did it this way I don't know but it is on the same curcuit to the ECM as the Fan temp switch. Like I said its the only thing left to check that no one else has mentioned.

thunderstick

is the temp staying up there at 240 when you're driving down the road too? not just when you stop somewhere? or is it cooling back down as you're rolling? if you replaced the fan switch with another stock one, they don't even come on til 237 or so anyways, so you won't see any improvement there. maybe i'm missing the big picture here... if you have dual fans, i thought the primary was driven by the fan switch only, secondary controlled by ecm if a/c is on, can't remember off the top of my head...

ScottR91RS

OK this may or may not help. I got my 91, 1 week ago. It is wired hot to the relay, and the fan ran continously. That burned the fan motor up. I have tried to locate this fan switch on a 3.1 and can't when I was at a Parts Yard I say 86 2.8 There was a Switch on it. The Relay make a Good Click When it gets ground Maybe use a test light to check for power With key on.