Hot Rod Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I bought my 16 year old daughter a 95 Camaro for her first car.

The car was bought from an auto auction yard as a private sale, not through the auction. The car was a repo.

It has the 3.4 V-6.

The fan does not come on when the coolant temp rises. I've replaced the fan switch at the top of the intake. I'm a bit confused here, because the "switch" seems more like a sensor. I'm getting a resistance reading across the leads, and not an open circuit.

When testing the switch in boiling water, the resistance goes down, but the switch never closes to become a completed circuit.

Even after replacing the switch, the fan won't come on.

I can get it to turn on when I turn on the A/C.

I can also get it to come on by disconnecting the plug at the fan switch. While this gets the fan to operate, I get a "check engine" light.


Second problem......

Since the car was repo'd, they bypassed the security system. They key supplied is not a security type key with the resistor in it. The "Security System" warning light is always lit. Chevy won't make a replacement key, without the original.

Any suggestions on which way to go about solving either of these problems?



Thanks,
 

·
Registered
Joined
·
143 Posts
not sure about the fan switch, sounds almost like a computer problem?? But for the ignition you will have to get a new ignition switch put in to get the passkey technology back... or deal with the light... The new ignition cost me about 800 dollars on my 94 Z28 about 4 years ago, so it might be worth dealing with the light, as long as there are no other adverse effects.
 

·
Registered
Joined
·
2,354 Posts
The cheap way is to go to the salvage yard and find a column with the coded key in it, and take the column and computer, then swap out with yours. (you could also just swap the prom and ignition switch, I think).

Trees
 

·
Time is short, are you ready?
Joined
·
655 Posts
human_forklift said:
The fan does not come on when the coolant temp rises. I've replaced the fan switch at the top of the intake. I'm a bit confused here, because the "switch" seems more like a sensor. I'm getting a resistance reading across the leads, and not an open circuit.
Most vehicles have a temp sensor and a temp switch. One in the intake and one in a cylinder head. If it is one wire, I would say it is a sensor. If there are two wires, it should be a switch. Also, it may be your relay(s) is bad. If the signal from the switch or the PCM is getting to the relay, but the relay is not closing, that may be your problem.

Regarding the security key, you may be able to have have the chip reworked to eliminate that feature. Even thought it is a V6, you may be able to get someone like Street & Performance to do it at a reasonable cost.

Here are few other possible reprogramming options:
1. Howell Engine Development
2. Speartech
3. Fuel Injection Specialties
4. Injection Technology
5. Fuel Injection, Inc.
6. TPI Tech (386) 437-1165 or (860) 599-0382 Not sure which number is the correct one :confused:

Good luck solving these problems, Ed www.edgesz28.com

__________________________________________________
Who is Jesus?.:)
 

·
Registered
Joined
·
179 Posts
You should be able to take your pink slip to the dealership and have them get you a key....just say you lost it. They will need the Vin # and proof of ownership. Make a huge stink if they say "no", because there is NO reason why they shouldn't do it for you....

The PCM controls the fans. Check the low speed fan relay, or fuse. You could always use tunercat software to program out the VATS (Vehicle Anti Thesft System), then you won't have to worry about the key, and you can also check trouble codes, and set fan on/off setpoints etc etc.... (www.tunercat.com)
The ECT sensor does not 'close'...it tells the PCM what the engine coolant temp is and the PCM controls various parameters....
Tim
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
Thanks to everyone for all the usefull information.

Of course.... I'm from the old school.... (as over-used as the phase is these days)

All I ever needed to run my hot rod as a teenager was to know how to set the dwell on a Mallory duel-point, jet a Holley double-pumper and adjust the solid lifters on the cam of choice.

I ran a 13 second 66 Chevelle all of my high school years. Never beat on the street, and only beat a handfull of times at the Fremont/Baylands Drag strip pn Wed. Nights.

Having a father who ran stock cars at the time and brought you up the ranks from a nine year old kid to a 16 year old who could build motors, and set up a stock car with the best of them didn't hurt.

Now, I can't even make a stupid electric fan turn on without having to buy software, cables and a laptop.

No wonder I started building custom motorcycles instead. Way simpler.....


Thanks again.
 

·
Registered
Joined
·
82 Posts
The intake sensor you checked is most likely the ECT or coolant sensor. Check the passenger side cyl head for a temp switch (single wire) between the rear most spark plugs. That would be the fan temp switch.

It is possible that the ECT controls the fans thru the computer
Maybe you didnt let the engine get hot enough. I have found that the cooling fans on newer cars are on at 229 and off at 219.
 

·
Registered
Joined
·
29 Posts
Sounds like maybe the old fan switch died and the PO accidently substituted a water temp sensor ?
 

·
Registered
Joined
·
1 Posts
This is going to sound stupid, but what in the ignition column might cause the fans not to work? A garage working in the ignition switch broke my turn signal lever, and high beam switch. My fans worked before they went to the garage, and work when manually powered. But the car won't turn them on. Replaced all of the sensors, and my problem sounds a lot luke the one above. First the ignition died, and now the fans don't work...
 

·
Hotrodders.com Moderator
Joined
·
8,096 Posts
Fans come on at around 230 degrees.
The coolant sensor, which you obviously have found feeds the PCM the value for the coolant temperature and the PCM turns on the fans accordingly.
To check it correctly, you have to scan a live data stream with a scanner and watch the coolant temp that the PCM is seeing.
The easiest way I found to check the Coolant temp sensor/PCM operation, is to grab a known good sensor,or a new one,unplug the connector fron the one on the car,plug the new one in, and heat it with a lighter while watching the data stream coolant temp value.You will need to have the key on, but don't run the motor, and it doesn't need to be hot. Just heat the sensor, watch the temp go up on the scanner then watch at what temp the fan kicks on.
Earlier Camaros had a redundant coolant fan switch, but I don't think a 95 does. The redundant was so redundant that it wouldn't turn on the fans until around 260. DUH. By then your motor is done anyway.
 

·
Registered
Joined
·
3,111 Posts
If you want to restore the anti-theft feature of the VATs....... perform the resistor bypass as described in the link, then place a hidden micro toggle in series with the resistor bypass...... flip the switch and the BCM doesn't see the correct value and will not allow the fuel injectors to function etc...... turn the switch on and the resistor fools the BCM etc...
 
1 - 13 of 13 Posts
Top