rad fan
#1
Advanced
Thread Starter
rad fan
when i got my 84 i had to replace the fan relay and the fusible link. 3 months later it wont turn off even with the key off. I was hoping you guys/gals could help me avoid the trial and error treadmill.
#2
Safety Car
The fan relay and its connector was a weak spot in the '84. Did you replace the relay with an original style relay? Is the connector in good shape, and not melted? Your relay, or the connector, has failed, and is providing a continual connection (short circuit) between the red (continuous 12 v.) and red (to the fan motor).
This relay is a common SPST configuration, so using the factory relay is not a requirement. Find a relay with a higher amperage rating (with mounting tab), even if you must rewire the harness with a different connector or spade lug terminals:
This relay is a common SPST configuration, so using the factory relay is not a requirement. Find a relay with a higher amperage rating (with mounting tab), even if you must rewire the harness with a different connector or spade lug terminals:
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84lover (03-13-2019)
#3
Le Mans Master
The fan relay and its connector was a weak spot in the '84. Did you replace the relay with an original style relay? Is the connector in good shape, and not melted? Your relay, or the connector, has failed, and is providing a continual connection (short circuit) between the red (continuous 12 v.) and red (to the fan motor).
This relay is a common SPST configuration, so using the factory relay is not a requirement. Find a relay with a higher amperage rating (with mounting tab), even if you must rewire the harness with a different connector or spade lug terminals:
This relay is a common SPST configuration, so using the factory relay is not a requirement. Find a relay with a higher amperage rating (with mounting tab), even if you must rewire the harness with a different connector or spade lug terminals:
Last edited by 84 4+3; 03-09-2019 at 07:10 PM.
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84lover (03-13-2019)
#4
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Thread Starter
I was thinking the relay was making the connection but i also thought because it was new I might be wrong. It's actually good news.
Thank you for your help. I knew there is good people here. Just to take time to reply to my problem is awesome.
Thank you again
Thank you for your help. I knew there is good people here. Just to take time to reply to my problem is awesome.
Thank you again
#8
Advanced
Thread Starter
no...which to me makes the relay the issue but three new relays didn't fix it. Hot Rod Roy suggested a different setup to avoid this relay...different plug and different relay
#9
Safety Car
The relay is NOT the problem! The problem is the CTS, or the wire from the CTS to the relay, or the switch in the a/c compressor. I've been taking these questions very slowly to minimize confusion.
With the relay plugged in, and the CTS unplugged, does the fan run? I presume you've figured out how to remove that tricky CTS connector? Squeeze the fat sides of the connector just right, and the connector will pull off easily.
If the fan runs, unplug the radiator fan switch connector in the top of the a/c compressor. If the fan still runs, you've got a short circuit to ground in the wire to the CTS or the compressor radiator fan switch.
If the fan doesn't run, you've got a bad CTS or pressure switch in your compressor. Please report back.
With the relay plugged in, and the CTS unplugged, does the fan run? I presume you've figured out how to remove that tricky CTS connector? Squeeze the fat sides of the connector just right, and the connector will pull off easily.
If the fan runs, unplug the radiator fan switch connector in the top of the a/c compressor. If the fan still runs, you've got a short circuit to ground in the wire to the CTS or the compressor radiator fan switch.
If the fan doesn't run, you've got a bad CTS or pressure switch in your compressor. Please report back.
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84lover (03-13-2019)
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84lover (03-13-2019)
#13
Advanced
Thread Starter
ok...found the one betwen 6 and 8
disconected that and the one betwen 1 and 3 and fan still runs...no master but i understand most of the diagram
disconected that and the one betwen 1 and 3 and fan still runs...no master but i understand most of the diagram
Last edited by 84lover; 03-13-2019 at 03:12 PM.
#14
Safety Car
In our '84's, the sensor between plugs 1 & 3 is for the instrument panel temp. gauge, and has nothing to do with the radiator fan.
Let's try a test to be sure we're on the right track: Pull the "fan" fuse from the fuse panel on the RH end of your dashboard. The "fan" fuse is in the second row, at the right end of the panel. Does your fan still run? You did pull all three connectors from the a/c compressor?
Let's try a test to be sure we're on the right track: Pull the "fan" fuse from the fuse panel on the RH end of your dashboard. The "fan" fuse is in the second row, at the right end of the panel. Does your fan still run? You did pull all three connectors from the a/c compressor?
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84lover (03-13-2019)
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84lover (03-13-2019)
#18
Safety Car
Bingo! That's the wrong relay. You need a four prong. A five prong will work, but only if you use the correct four prongs! Please refer to my wiring diagram. Be sure you observe NO ( normally open ) and NC ( normally closed ) contacts in the relay description. Your new relay should have a diode across the coil, as shown in the diagram. Be sure the cathode is connected to the +12 v. source. You may still have another problem, but let's fix one at a time!
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84lover (03-13-2019)
#19
Advanced
Thread Starter
i rechecked its four prong sorry...so its making a conection like A is closed...but if its not the relay why doesn't it run without the relay
Last edited by 84lover; 03-13-2019 at 04:32 PM.
#20
Advanced
Thread Starter
yes it has the diagram like your image i printedfrom your image i think the open a is closed due to another connection somewhere besides the relay....is that correct?
somehow that doesnt make sense since i have to plug it in
somehow that doesnt make sense since i have to plug it in
Last edited by 84lover; 03-13-2019 at 05:14 PM.