1989 Cooling Fan Problems
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
1989 Cooling Fan Problems
Hey guys. Haven’t had to make a post in a while and normally I’m good at figuring out my own problems but don’t really have the time right now and need the help from y’all.
So recently my my car started to want to overheat in traffic and traffic only. Doing some further investigation I found that both of my radiator fans were not working. Neither the aux (front of ac condenser) or main (aft of the radiator).
I got far far enough into it to fix the aux fan and it seems to work fine now or almost fine. Supposed to come on at around 238 if my research was right but comes on at roughly 242 which may just be an off dash reading. Also it allows The car not to overheat on a fairly cool day and by that I mean low to mid 80’s however I don’t know if that will be enough for hot days in traffic.
However for the main main fan I am getting absolutely nowhere with it an am not sure exactly how to go about the trouble shooting process of it as I haven’t done a whole lot of research yet.
The furthest I’ve gotten is checking the fan itself which is a brand new spal fan and works great on the bench. And I did a quick test to turn on the fan by grounding out the aldl in which gave me a bad result. I know before when I’d ground it out to check codes it would for sure turn the fan on however now it does nothing whatsoever when grounded in sense of turning the fan on.
Let me know now where I should go from here. I have an fsm but it is packed away from my recent move and is nowhere to be found yet otherwise I’d probably have it figured out. I’m hoping y’all are able to pull through for me on this lol and I know y’all are the experts on these cars. Thank you
So recently my my car started to want to overheat in traffic and traffic only. Doing some further investigation I found that both of my radiator fans were not working. Neither the aux (front of ac condenser) or main (aft of the radiator).
I got far far enough into it to fix the aux fan and it seems to work fine now or almost fine. Supposed to come on at around 238 if my research was right but comes on at roughly 242 which may just be an off dash reading. Also it allows The car not to overheat on a fairly cool day and by that I mean low to mid 80’s however I don’t know if that will be enough for hot days in traffic.
However for the main main fan I am getting absolutely nowhere with it an am not sure exactly how to go about the trouble shooting process of it as I haven’t done a whole lot of research yet.
The furthest I’ve gotten is checking the fan itself which is a brand new spal fan and works great on the bench. And I did a quick test to turn on the fan by grounding out the aldl in which gave me a bad result. I know before when I’d ground it out to check codes it would for sure turn the fan on however now it does nothing whatsoever when grounded in sense of turning the fan on.
Let me know now where I should go from here. I have an fsm but it is packed away from my recent move and is nowhere to be found yet otherwise I’d probably have it figured out. I’m hoping y’all are able to pull through for me on this lol and I know y’all are the experts on these cars. Thank you
Zen Vet Master Level VII
Joined: Mar 2016
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From: Southlake, TX
Does your fans come on when you put your AC on? It should and that will be a start.
You may have problems with your coolant temp sensors or wires.
I'm confused when you say "The ALDL game me a bad result".... what does that mean?
You may have problems with your coolant temp sensors or wires.
I'm confused when you say "The ALDL game me a bad result".... what does that mean?
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
The ac is a no go. Turning on the ac has no effect on fan operation either. I’ll check the sensors and see what I get from those.
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
Seems to me like a bad relay for the main fan. Both fans get their control power from the same fuse COOL FAN 3 Amp, so if the little fan runs, that fuse is good. Because the ECM doesn't turn on the fan with the ALDL grounded, I would look at the relay. The other possibility would be the fuse link for the main fan. Easy to test: Disconnect the relay and jumper the red to the other large gauge wire which should be the fan motor. (I don't know the color of this wire in 89 off-hand).
There's some ideas.
There's some ideas.
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Last edited by GREGGPENN; Apr 29, 2018 at 02:06 AM.
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
So here is what my findings are. I have continuity from blue wire in relay to ground and just barely. Grounding the green wire gives me no effect of making the relay click and I tried it with 2 different relays. If I check for voltage in the red input wire I have no voltage with key on or off. If I apply direct battery power to the main wire from the relay to the fan the fan turns on and operates as normal.
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
Racer
Joined: Jun 2017
Posts: 343
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From: Newport News VA
So here is what my findings are. I have continuity from blue wire in relay to ground and just barely. Grounding the green wire gives me no effect of making the relay click and I tried it with 2 different relays. If I check for voltage in the red input wire I have no voltage with key on or off. If I apply direct battery power to the main wire from the relay to the fan the fan turns on and operates as normal.
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
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So here is what my findings are. I have continuity from blue wire in relay to ground and just barely. Grounding the green wire gives me no effect of making the relay click and I tried it with 2 different relays. If I check for voltage in the red input wire I have no voltage with key on or off. If I apply direct battery power to the main wire from the relay to the fan the fan turns on and operates as normal.
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
So from this im gonna have to say it’s time to start checking fusible links. Anyone know off the top of there head which fusible link is the mess is for the fan? Also what’s the best and cleanest way to replace fusible links?
The blue wire should show 12+V (supplied by 10A fuse) which doesn't match what is SEEMED you were looking for. Blue is the power feed to the trigger side of the relay...which is energized by ECM grounding the grn/wht wire. (IOW...it's not normally grounded).
The red wire should show the same positive voltage (from fusible link). The remaining wire (blk?) is the main ground for the power side of the relay.
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Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
You are correct. Sorry about that. Got my own words confused. Blue wire was showing continuity through positive terminal with power on I believe, however I did not check voltage for it and will tomorrow. And there is 4 wires. Blue +12 as you said which I am getting continuity through. Green for ground side of relay which I just found needs the engine running to be able to function properly in this circuit. Red for main battery power which shows no voltage. Black/red for the fan which if I jump +12 directly to it allows the fan to function. All checking out good except the red wire for main power. I’m gonna donsome wire digging on the main power for the relay and the fusible link side and see what I can find. Thanks all for the help so far.
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
I had found a couple of my links cracked at the original factory butt connectors. All I had to do was hit them with a couple new butt connectors and they were fine. It's getting harder to find decent fusible link now, I try to use the factory original if I can. O'Reilly's has a decent selection of fusible link if it needs complete replacing. I don't remember off the top of my head which is which, but it's easy enough to pop the body panel, battery and battery tray out so you have access to everything there. Tracing that circuit is super simple, had to do it for my 89 as well
Race Director
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Along with being high enough temp for the ECM to command main fan operation -- when it closes the ground circuit to energize the relay. I reprogrammed my turn-on temp years ago (383 build). Seems like OEM main fan turn-on temp is up in the high 220's? Aux is 238 IIRC.
Last edited by GREGGPENN; May 1, 2018 at 01:37 PM.
Thread Starter
Burning Brakes
Joined: Mar 2012
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From: California
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St. Jude Donor'13
Ok here’s an update.
Found fhe bad fusible link. It was very intermittent and would you only give continuity if you wiggled it in the perfect direction. Figured this was ultimately my problem. Well I was wrong.
Started up the car got it to the correct temp of roughly 228 and got absolutely nothing from the fan. Let the car run until the aux fan kicked on at 238ish.
I pulled the relay and checked to see my readings.
Red wire has 14+ with car running and shows excellent continuity to the junction block Behind the battery. However if you check continuity from the relay wire to the battery directly the continuity is not so great showing about 80 ohms. I also check continuity from the battery to the junction block and was getting an excellent reading as well.
I would think having the voltage it would be fine and still operate. I guess next step is to check and see if the relay will come on by grounding the green/white wire and report back. Probably should’ve done it while I was doing the rest but got called into work and will hopefully be done soon.
Let me know your thoughts. Thank you all for the help so far.
Found fhe bad fusible link. It was very intermittent and would you only give continuity if you wiggled it in the perfect direction. Figured this was ultimately my problem. Well I was wrong.
Started up the car got it to the correct temp of roughly 228 and got absolutely nothing from the fan. Let the car run until the aux fan kicked on at 238ish.
I pulled the relay and checked to see my readings.
Red wire has 14+ with car running and shows excellent continuity to the junction block Behind the battery. However if you check continuity from the relay wire to the battery directly the continuity is not so great showing about 80 ohms. I also check continuity from the battery to the junction block and was getting an excellent reading as well.
I would think having the voltage it would be fine and still operate. I guess next step is to check and see if the relay will come on by grounding the green/white wire and report back. Probably should’ve done it while I was doing the rest but got called into work and will hopefully be done soon.
Let me know your thoughts. Thank you all for the help so far.
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 769
Likes: 22
From: California
FL Events Coordinator
St. Jude Donor'13
Well as it seems I had a bad relay out of the box. Relay would click perfectly fine when activating but would not allow voltage to pass through it.
Swapped it it with another relay and everything is now working perfectly fine and I have the old relay installed in its place.
So it is safe to assume that the fusible link link was the sole cause of the problem and it only cost me $8 and a couple hours worth of work to troubleshoot and replace to have a correctly working cooling system again.
Swapped it it with another relay and everything is now working perfectly fine and I have the old relay installed in its place.
So it is safe to assume that the fusible link link was the sole cause of the problem and it only cost me $8 and a couple hours worth of work to troubleshoot and replace to have a correctly working cooling system again.
Racer
Joined: Jun 2017
Posts: 343
Likes: 18
From: Newport News VA
Well as it seems I had a bad relay out of the box. Relay would click perfectly fine when activating but would not allow voltage to pass through it.
Swapped it it with another relay and everything is now working perfectly fine and I have the old relay installed in its place.
So it is safe to assume that the fusible link link was the sole cause of the problem and it only cost me $8 and a couple hours worth of work to troubleshoot and replace to have a correctly working cooling system again.
Swapped it it with another relay and everything is now working perfectly fine and I have the old relay installed in its place.
So it is safe to assume that the fusible link link was the sole cause of the problem and it only cost me $8 and a couple hours worth of work to troubleshoot and replace to have a correctly working cooling system again.
