Coolant Fan Not Coming On.
07-06-2005, 06:44 PM
#1
Burning Brakes
Thread Starter
Member Since: Apr 2005
Location: JUPITER FLORIDA
Posts: 1,110
Likes: 0
Received 0 Likes
on
0 Posts
Coolant Fan Not Coming On.
Hey guys,
My 86' just overheated today because the coolant fan would not come on. it has been working fine and then all of a sudden it is not. i checked the fuse and it was fine, i grounded the a and b terminals on the aldl and the fan did not kick on when i turned the power on. does this mean the fan is burnt out? or could there still be a problem with the sensors or the wiring. I checked the sensors and the one on the connection to the one on the head (pasenger side) was pretty nasty and the one one the intake manifold was fine. Please help! im vettless right now, i dont want to burn her up!
My 86' just overheated today because the coolant fan would not come on. it has been working fine and then all of a sudden it is not. i checked the fuse and it was fine, i grounded the a and b terminals on the aldl and the fan did not kick on when i turned the power on. does this mean the fan is burnt out? or could there still be a problem with the sensors or the wiring. I checked the sensors and the one on the connection to the one on the head (pasenger side) was pretty nasty and the one one the intake manifold was fine. Please help! im vettless right now, i dont want to burn her up!
07-06-2005, 06:52 PM
#2
Race Director
Member Since: Sep 2000
Location: The Top of Utah
Posts: 17,298
Likes: 0
Received 23 Likes
on
22 Posts
Originally Posted by cplonner
Hey guys,
does this mean the fan is burnt out? or could there still be a problem with the sensors or the wiring.
does this mean the fan is burnt out? or could there still be a problem with the sensors or the wiring.
Originally Posted by cplonner
I checked the sensors and the one on the connection to the one on the head (pasenger side) was pretty nasty
RACE ON!!!
07-06-2005, 07:37 PM
#4
Race Director
Member Since: Sep 2000
Location: The Top of Utah
Posts: 17,298
Likes: 0
Received 23 Likes
on
22 Posts
Originally Posted by cplonner
When you said of course did you mean the fan? or the sensor?
Originally Posted by cplonner
does this mean the fan is burnt out? or could there still be a problem with the sensors or the wiring.
RACE ON!!!
07-06-2005, 09:00 PM
#6
Team Owner
Member Since: Dec 2000
Location: SE NY
Posts: 90,675
Likes: 0
Received 300 Likes
on
274 Posts
Cruise-In II Veteran
Start at the battery + terminal and follow the Orn fusable link to the weather pack connector and then the Red wire to the fan relay.
If the fusable link is in tact jumper the Grn/Wht wire at the fan relay to ground and turn on the ignition. If the fan does not come on, open the connector at the fan and jumper one side to ground and the other side to +12Vdc, just tough the jumper to +12Vdc in case the fan motor is shorted internally.
If the fusable link is in tact jumper the Grn/Wht wire at the fan relay to ground and turn on the ignition. If the fan does not come on, open the connector at the fan and jumper one side to ground and the other side to +12Vdc, just tough the jumper to +12Vdc in case the fan motor is shorted internally.
07-06-2005, 09:57 PM
#7
Burning Brakes
Thread Starter
Member Since: Apr 2005
Location: JUPITER FLORIDA
Posts: 1,110
Likes: 0
Received 0 Likes
on
0 Posts
my neighboor and i just looked at it with a voltemeter and everthing looks good, the relay is my only suspision now. hopfully replacing that will fix it nice and easy. i think that would explain the reason the fan doesnt come on when i jump the a&b terminal in the aldl.
07-07-2005, 10:14 AM
#9
Race Director
Unplug your fan, run a pair of wires from your battery pos/neg down to the fan with a pair of alligator clips, turn the ignition on, if the fan does not spin, then your fan is bad, or if your fan does indeed spin, does it get hot quickly,,,,
07-07-2005, 11:13 AM
#10
Race Director
Member Since: Sep 2000
Location: The Top of Utah
Posts: 17,298
Likes: 0
Received 23 Likes
on
22 Posts
Originally Posted by LD85
Unplug your fan, run a pair of wires from your battery pos/neg down to the fan with a pair of alligator clips, turn the ignition on,
RACE ON!!!
07-07-2005, 03:21 PM
#12
Race Director
Originally Posted by CFI-EFI
I don't understand the point of turning the ignition on, when you are jumping directly from the battery to the fan motor.
RACE ON!!!
RACE ON!!!
07-07-2005, 04:32 PM
#13
Burning Brakes
Thread Starter
Member Since: Apr 2005
Location: JUPITER FLORIDA
Posts: 1,110
Likes: 0
Received 0 Likes
on
0 Posts
ok i replaced the relay and nothin....i took a look at the fusable links and they are all crusty and brown. im gonna go ahead a say i will replace them next, they look pretty bad. at the auto part store do i just ask for a fusable links? and tell them the wire gage?
07-07-2005, 06:40 PM
#14
Team Owner
Member Since: Dec 2000
Location: SE NY
Posts: 90,675
Likes: 0
Received 300 Likes
on
274 Posts
Cruise-In II Veteran
Good question on the fusable links.
When I was installing new connector tips onto mine I noticed they are just thin gauge wire with a rubber jacket that melts when they overheat.
My '85 GM Shop Manual says they are 20 gauge.
Are you sure that you are getting no power to the Red wire at pin D of the relay?? Also you should be getting +12 Vdc on the Dk Blu wire to pin C of the relay, in Run only. If both these conditions are met you should be able to get +12 Vdc on the Blk/Red wire from relay pin A by grounding the Grn/Wht wire at pin B, with the ignition switch in Run.
When I was installing new connector tips onto mine I noticed they are just thin gauge wire with a rubber jacket that melts when they overheat.
My '85 GM Shop Manual says they are 20 gauge.
Are you sure that you are getting no power to the Red wire at pin D of the relay?? Also you should be getting +12 Vdc on the Dk Blu wire to pin C of the relay, in Run only. If both these conditions are met you should be able to get +12 Vdc on the Blk/Red wire from relay pin A by grounding the Grn/Wht wire at pin B, with the ignition switch in Run.
Last edited by 65Z01; 07-07-2005 at 06:46 PM.
07-07-2005, 06:47 PM
#15
Burning Brakes
Thread Starter
Member Since: Apr 2005
Location: JUPITER FLORIDA
Posts: 1,110
Likes: 0
Received 0 Likes
on
0 Posts
ok here is the deal. i checked, fusable links (the wires are still intact just the outside of the splice looks nasty), i put a new relay in (no luck) i grounded the a&b terminals (nothin) and i cannot get to the electric plug for the fan without breakin the clip, is there another way to test the fan? i either have to take the whole fan outa there to get to the clip, or break it somehow. Any suggestions?
07-07-2005, 06:54 PM
#16
Team Owner
Member Since: Dec 2000
Location: SE NY
Posts: 90,675
Likes: 0
Received 300 Likes
on
274 Posts
Cruise-In II Veteran
As I suggestted above, perform the test to see if there is +12Vdc on the Red/Blk wire at the relay.
If so, pierce the Red/Blk wire just near the fan motor to see if there is +12Vdc there. If not there is an open in the power line to the fan.
If so do the same to the Blk wire from the fan motor. This wire should have 0 Vdc. If not there is an open in the Gnd wire from the fan.
If so, remove the fan shroud and replace the fan motor.
If so, pierce the Red/Blk wire just near the fan motor to see if there is +12Vdc there. If not there is an open in the power line to the fan.
If so do the same to the Blk wire from the fan motor. This wire should have 0 Vdc. If not there is an open in the Gnd wire from the fan.
If so, remove the fan shroud and replace the fan motor.