TX-SleeperC5

iTrader: (2)

We have a 1987 Trans Am GTA. The problem is one of the radiator cooling fans isn't running anymore. Checked to see that it spins freely and it does. I'm thinking possibly a relay.

Anyone have any suggestions ?

Bob88GTA

iTrader: (2)

Check relay first. When is your fan set to come on? Stock program? Temp wise? Second fan comes on for AC.

Unplug motor and put voltage to the motor to see if it runs, If not, bad motor, if it does, could be a relay or temp switch. Check ground also


Unless this was all screwed up by adding switches and the like

TX-SleeperC5

iTrader: (2)

the car has stock programing. single fan runs all the time (drivers side). The second fan never comes on. Even when the AC is turned on.

Bob88GTA

iTrader: (2)

humm, drivers should not kick in till around 220 ish, not exactly sure, SHOULD NEVER always run unless it was hard wired to ignition ON. But, if that's the case, the motor run itself to death.

Sounds like the AC fan was wired to run all the time too and it also burnt up. Are you the original ower or other?

TX-SleeperC5

iTrader: (2)

3rd owners of the car.... Look like I'll have to do some wiring harness digging OR take it to my buddy at the local Chevy dealership and have them take a look....

Bob88GTA

iTrader: (2)

Before I would take it to Chevy, at least check the fans one by one by unplugging and putting voltage to them. That would tell ya if they are toast or not. Get a manual and run the wiring checks. Wiring diagram is on here, just do a search, I've seen it. If its all butchered up, Chevy might take you to the bank or just tell you kindly to take it else where. Hate to say it.

Ozz1967

iTrader: (4)

The second fan, if the motor isn't toast, is run via the fan switch in the passenger side head, just forward of the dipstick. When engine gets to temp, switch grounds, sends signal through relay to fan. Since it doesn't work with the AC on, which it should, means either the fan is toast, or the relay is toast, or both. You can jumper the relay by the big red power lead on it...but check to see if the fan works with power to it. If it does, we'll go from there.

TX-SleeperC5

iTrader: (2)

cool !
checking the fan was going to be the first order of business.... Will post findings later.

deadbird

Odd tidbit... '87 (only...maybe 86 but, don't have manual for that), the second fan ran only with the fan switch at 238° (stock fan switch temp for all fbodys, excluding TTA). '87 was transition year from single to dual fans. Second fan wiring was cobbled into harness wiring. '88 got new relays and secondary fan was tied to a/c.

Primary fan will run key on if a/c has been yanked and fan request wire from a/c line is not grounded... this was reversed in '88, too.

Ground the fan switch wire, key on. If it runs, its fine.

Reid Fleming

iTrader: (2)

deadbird has it correct. 87 cars only turned on the passenger fan when the coolant temp reached 235'ish degrees. So I'd bet that the fan actually does work, but you're never getting up that high.

TX-SleeperC5

iTrader: (2)

The temp gauge in the car is shot and needs to be replaced. But per my son, the car overheated one time and boiled over. Which is how I know the second fan isnt working, even when the car is at full temp or the AC is turned on.