moo2

What would make the cooling fan to come on with the key. The ac is off and it didn't do this when I put it away last year.

caddyboy84

Hung-up relay or temp switch. Disconnect the battery and then see what happens.

moo2

Here is the relay located?

caddyboy84

On my 88 it's on the driver wheel-well near the battery.

rodj

Helps to mention the year model when asking questions
Many differences in systems across the years; esp in fan control
Engine in limp home turns on fans with key.
Pull the engine codes and see if anything showing

rodj

What does that achieve?
If you disconnect the battery it kills everything electrical

caddyboy84

I obviously meant to reset the system

caddyboy84

I'd like to think that everyone here has enough of a handle on things to not need it spelled out

Black89Z51

Check the temp switch, then check the relay as stated before.

Dr.Huxtable

The computer controls the Main fan with inputs from the coolant temperature sensor in front of the intake, vehicle speed sensor, and A/C system.

Start from the front and work your way back. It's not uncommon for a bad ECM to be the cause, that's what happened to me. There is a dark green wire w/ a white stripe that comes off of the main fan relay, this is what the computer grounds to turn on the main fan after it receives inputs from the above sensors.

When you turn your key to the RUN position without the car started, does the fan turn on?

http://forums.corvetteforum.com/c4-t...-start-up.html

gunnerjuju

Last summer my fan stayed running even after I shut the car off. I disconnected the relay and reconnected it and all has been well since then. I do plan on replacing all relays (MAF, Fuel pump etc)

rodj

You would be surprised with the lack of basic knowledge of the current crop of newbie owners
Going by some of the recent questions I suspect many would struggle to change a tire

caddyboy84

I have seen some stupid answers as well as questions. None of us really know everything. I did notice that a lot of answers people give jump into a more technical direction instead of searching the more obvious first. Ya gotta let the poor guy see if it's relays and sensors first and if not, then we tell him his computer is FRIED or if he has the proper air pressure in his rear tires, the fan will start working You're right though, I have seen answers like that to questions that had nothing to do with tires

moo2

The fan does come on with the key. If I unhook the single wire on the AC pump, it turns off.

rodj

Because the broad assumption is ( at least it used to be ) that the guy had enough brains
to do the obvious checks like confirming gas in his tank ( not just going by the fuel gauge )
before asking why his car won't start

caddyboy84

caddyboy84

Ok ok........Lets not beat up on the "youngins". UHhhhh, what were we talking about again OH YEAH, FANS ON, try looking into a hung-up A/C relay first, then I would trouble shoot the A/C controlls. Sorry moo, we're just some old guys venting a little, you know the deal.