Should the fan turn on when ignition is turned on?
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
Should the fan turn on when ignition is turned on?
I was just curious if this is normal. Someone told me it wasn't. I noticed that it does turn off though when i pull trouble codes. Any ideas? Thanks.
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Car: 91 Camaro Vert
Engine: 02 LS1, HX40
Transmission: 2002 LS1 M6
if the ignition is on, AND the coolent temp is high enough, yes it should come on.
if the coolent temp isnt hot, no.. it shouldnt ALWAYS come on when the ignition power is on.
if the coolent temp isnt hot, no.. it shouldnt ALWAYS come on when the ignition power is on.
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
AC is off. It doesn't really look like anyone messed with the wiring but it is possible. Not that it is a huge deal to have it running. I just don't want to burn the motor on it.
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Car: 89 camaro rs
Engine: 305 tbi
Transmission: 700r4
i just found that its on driver's side firewall, by the master cylinder. It has 4 wires going to it. the fuel pump relay has 5 wires going to it. i hope this helps.
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Car: 89 Firebird
Engine: 355
Transmission: 700
Re: Should the fan turn on when ignition is turned on?
Originally posted by trueburton
I was just curious if this is normal. Someone told me it wasn't. I noticed that it does turn off though when i pull trouble codes. Any ideas? Thanks.
I was just curious if this is normal. Someone told me it wasn't. I noticed that it does turn off though when i pull trouble codes. Any ideas? Thanks.
Are you getting codes when you check them?
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
I am not sure about that. I geuss it's a possibility. Those are pretty cheap aren't they? maybe I'll just pick one up for sheets and giggles. Is that the plug that is like a 7/8" on the Pass side head and is a pain to get to?
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Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
You either have an unplugged or btoken fan switch. It is located in the passenger side head. When damaged the fan comes on automatically as a safety measure.
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Car: 89 camaro rs
Engine: 305 tbi
Transmission: 700r4
Originally posted by ShiftyCapone
You either have an unplugged or btoken fan switch. It is located in the passenger side head. When damaged the fan comes on automatically as a safety measure.
You either have an unplugged or btoken fan switch. It is located in the passenger side head. When damaged the fan comes on automatically as a safety measure.
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Car: one with wheels
Engine: one with pistons
Transmission: one with gears
You aren't by chance leaving the A & B pins connected with the paperclip/etc. when you are turning on the car?
#22
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I don't see how disconnecting the fanswitch wire, can cause the fans to run?
Fanswitch decreases in resistance when it gets warmer.
High resistance assumes colder. Ultimate cold would be an open/disconnected wire.
Someone care to explain how for me?
Fanswitch decreases in resistance when it gets warmer.
High resistance assumes colder. Ultimate cold would be an open/disconnected wire.
Someone care to explain how for me?
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
From what I understand, as stated earlier, the fans come on as a precaution if they are disconnected. However my fan goes off when I start the engine until it warms up and then the fans kick back on as they are supposed to. I am a little confused.
#25
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Nevermind, I'll tell you how the dual fan setup works....
primary is controlled via the CTS in the intake, sends the resistance to the ECM, ECM interpets for temp and (via ECM setting) turns on the primary fan.
Secondary fan is controlled via Fanswitch, also grounds the primary (on my '89 anyways) fan, energizes both relays and both fans turn on.
Also, A/C high pressure switch activates the 2ndry line on my '89, again, activates both primary and 2ndry fans.
There is no "fail safe" mode on my '89 (very, very, very similar to your '87.
In fact I have a 91RS TBI that...son of a gun...with the fanswitch disconnected doesn't energize the fan either.
primary is controlled via the CTS in the intake, sends the resistance to the ECM, ECM interpets for temp and (via ECM setting) turns on the primary fan.
Secondary fan is controlled via Fanswitch, also grounds the primary (on my '89 anyways) fan, energizes both relays and both fans turn on.
Also, A/C high pressure switch activates the 2ndry line on my '89, again, activates both primary and 2ndry fans.
There is no "fail safe" mode on my '89 (very, very, very similar to your '87.
In fact I have a 91RS TBI that...son of a gun...with the fanswitch disconnected doesn't energize the fan either.
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by slayer2000
any chance the plug for the temp switch is damaged? When I swapped my heads I left it unplugged and the fans would come on all the time.
any chance the plug for the temp switch is damaged? When I swapped my heads I left it unplugged and the fans would come on all the time.
First determine which fan is turning on, one, or are both turning on?
The following is possible:
1) One, or both fan relays have failed closed. The heavy duty fan relay is on the fender near the coolant resevoir, the primary fan relay is on the firewall behind the brake booster.
2) The A/C fan switch has failed closed only if the heavy duty fan is on with A/C off, and the ignition on. with the fan on unplug the connector, it's bad if the fan stops.
3) The ECM controls the primary fan, and it's fan solid state switch can fail closed leaving the fan relay coil connected to ground. No codes, no problems with the rest of the ECM.
4) If the ECM eprom has been changed, or reprogrammed the primary fan may come on with the ignition. When I updated my 1988 program with the 1989 $6E to delete the cold start system, I had to change the "Normally Open Fan Request Input" from closed to open because the program was for a 1989 Corvette.
#27
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
The weird thing is though that the fan comes on when I turn the ignition on. But it is not on once i start the engine. The fan will then later come on when engine warms up to like 200 degrees or whatever the stock setting is. So wouldn't that eliminate the possibility of a failed relay? Oh yeah it is the driver side fan that comes on.
#28
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I have an indicator light on my 88, the fans do come on when starting the engine, go off pretty quickly. Never understood this either but it doesn't seem to cause any problems. The secondary sensor is a switch, on or off, can't imagine this having this effect when unhooked.
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by trueburton
The weird thing is though that the fan comes on when I turn the ignition on. But it is not on once i start the engine. The fan will then later come on when engine warms up to like 200 degrees or whatever the stock setting is. So wouldn't that eliminate the possibility of a failed relay? Oh yeah it is the driver side fan that comes on.
The weird thing is though that the fan comes on when I turn the ignition on. But it is not on once i start the engine. The fan will then later come on when engine warms up to like 200 degrees or whatever the stock setting is. So wouldn't that eliminate the possibility of a failed relay? Oh yeah it is the driver side fan that comes on.
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
Originally posted by rgarcia63
Driver's side is primary fan controlled by ECM. That would be item #4.
Driver's side is primary fan controlled by ECM. That would be item #4.
#31
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
When I bought this car is was completely stock so I doubt the PROM was modified at all. Could it be something esle?
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by trueburton
When I bought this car is was completely stock so I doubt the PROM was modified at all. Could it be something esle?
When I bought this car is was completely stock so I doubt the PROM was modified at all. Could it be something esle?
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
Yes kind of... it comes on when ignition is on, engine off. Then when I start the engine, it is off until the engine reaches High temp.
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by trueburton
Yes kind of... it comes on when ignition is on, engine off. Then when I start the engine, it is off until the engine reaches High temp.
Yes kind of... it comes on when ignition is on, engine off. Then when I start the engine, it is off until the engine reaches High temp.
The EPROM in my '88 is OEM, but I erased it, and reprogrammed it with '89 ARP binary file. My fan is off with the engine off and comes on when I test for codes, you says your's does the opposite that's why I suspect the ECM firmware switch.
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
Yes but as previously stated, When I bought my car it was completely stock. Not even nice spark wires or filters or any basic upgrades so I doubt that the EPROM was reprogrammed. But I geuss it is possible.
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Car: '92 Z28
Engine: L98
Transmission: 700R4
Originally posted by trueburton
Yes kind of... it comes on when ignition is on, engine off. Then when I start the engine, it is off until the engine reaches High temp.
Yes kind of... it comes on when ignition is on, engine off. Then when I start the engine, it is off until the engine reaches High temp.
Al.
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Car: '88 Red Trans Am w/ T-tops
Engine: 305 TPI
Transmission: T-5
I have already replaced the ECM once and the car did this same thing since I bought it so I don't think it has anything to do with a BAD ECM. I'll try tapping it though. See what happens.
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