I've got and 88 IROC w/ 350. The cooling fans run all the time (when the key is on). Could it be a sensor? If so, any suggestions.
It was suggested to me that it may be in limp mode (computer problem). The car runs like a beast though.

Is the check engine light on? Does it even work? If those are ok, look for a previous owner to have hard wired them to run all of the time or maybe put them on a switch that has been left on.

Now, if you've had this car for a while and this has just started happening...then I'm back to limp home mode.

Is the check engine light on? Does it even work? If those are ok, look for a previous owner to have hard wired them to run all of the time or maybe put them on a switch that has been left on.

Now, if you've had this car for a while and this has just started happening...then I'm back to limp home mode.

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But, if it just started happening, and the the CEL is not on and passes the bulb check, then I'd be looking at the fan switch and it's wiring.

:1:

I'd be looking at the fan switch and it's wiring.
I do believe in 88 the fan was still triggered by the ECM, not a switch (could be wrong on this one)
Another thing to look for is the fan realy contacts welded together.

Yeah, remember my woes I had in summer '05 with my fan, that was on my '85 which some to find 86 & up used the switch on the passanger side. I'm pretty sure my T/A also a '88 has it.