How to test fans to see if they're working?
07-15-2012, 08:03 PM
#1
How to test fans to see if they're working? First off, its my '97 SS LT1 (car in sig)
Ok I've noticed that my cars temp will slowly climb when I drive it around town. Almost 3/4 of the way (like almost 240ish or so??) so I shut the car down to cool off. I popped the hood and don't notice or hear the fans coming on.
Recently I have replaced the t-stat with a 160*, I let the air out of the bleeder screw, topped off coolant and checked all hoses and radiator is good.
So, I figured I'll just wire in a manual fan switch, AND STILL fans won't come on. I got a DPDT switch and did the correct grounding and splicing into the dark blue/dark green wires of the fan wires that are on the connector near the passenger top fender.
I also took out the fog lamp relay and switched it in all 3 fan relays, and still a no go. I heard if I did a jumper wire from port 5 to 6 on the DLC connector it will work, NOTHING.
So I know there has to be a few other ways to directly power the fans to test if they work right? If I run my car and idle it with the A/C on, fans should automatically come on? And if I ground a wire to the fans fuse, will it kick them on? Any help is appreciated before I start throwing parts at the car. THANKS!!!
Ok I've noticed that my cars temp will slowly climb when I drive it around town. Almost 3/4 of the way (like almost 240ish or so??) so I shut the car down to cool off. I popped the hood and don't notice or hear the fans coming on.
Recently I have replaced the t-stat with a 160*, I let the air out of the bleeder screw, topped off coolant and checked all hoses and radiator is good.
So, I figured I'll just wire in a manual fan switch, AND STILL fans won't come on. I got a DPDT switch and did the correct grounding and splicing into the dark blue/dark green wires of the fan wires that are on the connector near the passenger top fender.
I also took out the fog lamp relay and switched it in all 3 fan relays, and still a no go. I heard if I did a jumper wire from port 5 to 6 on the DLC connector it will work, NOTHING.
So I know there has to be a few other ways to directly power the fans to test if they work right? If I run my car and idle it with the A/C on, fans should automatically come on? And if I ground a wire to the fans fuse, will it kick them on? Any help is appreciated before I start throwing parts at the car. THANKS!!!
07-16-2012, 08:59 AM
#3
A Power Probe is the **** for testing circuits & powering up things such as fans Itll test continuity , power a circuit, ground a circuit & tell you if its a short Best 120 bucks I ever spent on the Power Probe 2 Wish I had the newest one with a 12v display 
Its helped trace down many problems
Its helped trace down many problems
07-16-2012, 03:12 PM
#4
A Power Probe is the **** for testing circuits & powering up things such as fans Itll test continuity , power a circuit, ground a circuit & tell you if its a short Best 120 bucks I ever spent on the Power Probe 2 Wish I had the newest one with a 12v display Its helped trace down many problems
Its helped trace down many problemsThe fans are connected in parallel on high and in series on low.
http://shbox.com/1/fan_schematic_1995.jpg
Al
07-16-2012, 05:31 PM
#6
http://www.radioshack.com/product/in...62397#inTheBox
Al 95 Z28
07-17-2012, 11:31 PM
#7
Well I took the fans out (what a PITA! lol) and tested directly with power. The left (driver) side fan will turn on but the right (passenger) side will not turn on at all. It actually barely powered on for about a half second, but after that would never turn on.
If I tested everything the way I did, I wonder why the fans never come on with the car running? I have a feeling I'm going to be chasing this....
If I tested everything the way I did, I wonder why the fans never come on with the car running? I have a feeling I'm going to be chasing this....
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07-18-2012, 02:56 AM
#8
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Don't even read another post man, I have the answer! lmfao I had the exact same problem to a T and couldn't figure it out until just recently.
A - you have dead fans, which you're about to find out
B, which is my problem - My fans weren't coming on until my car got up 3/4 on the temp gauge from standing still... after a lot of messing around I'm 99% sure this is attributed to either a bad oil sensor, or coolant temp sensor, or both in my case. While it's going to get fixed when I get my tune, I'm still going to replace those sensors.
I went through so much BS even thinking I had a bad head gasket lol.. i knew the fans were coming on so I didn't think anything of it, but they weren't coming on when they were supposed to. Same thing.. car runs perfect, no problems, no codes, runs cool when moving, never overheats, new 160 t stat, new water pump, new radiator, nothing out of the norm whatsoever.
God damned fans lol
A - you have dead fans, which you're about to find out
B, which is my problem - My fans weren't coming on until my car got up 3/4 on the temp gauge from standing still... after a lot of messing around I'm 99% sure this is attributed to either a bad oil sensor, or coolant temp sensor, or both in my case. While it's going to get fixed when I get my tune, I'm still going to replace those sensors.
I went through so much BS even thinking I had a bad head gasket lol.. i knew the fans were coming on so I didn't think anything of it, but they weren't coming on when they were supposed to. Same thing.. car runs perfect, no problems, no codes, runs cool when moving, never overheats, new 160 t stat, new water pump, new radiator, nothing out of the norm whatsoever.
God damned fans lol
07-18-2012, 03:38 AM
#9
Don't even read another post man, I have the answer! lmfao I had the exact same problem to a T and couldn't figure it out until just recently.
A - you have dead fans, which you're about to find out
B, which is my problem - My fans weren't coming on until my car got up 3/4 on the temp gauge from standing still... after a lot of messing around I'm 99% sure this is attributed to either a bad oil sensor, or coolant temp sensor, or both in my case. While it's going to get fixed when I get my tune, I'm still going to replace those sensors.
I went through so much BS even thinking I had a bad head gasket lol.. i knew the fans were coming on so I didn't think anything of it, but they weren't coming on when they were supposed to. Same thing.. car runs perfect, no problems, no codes, runs cool when moving, never overheats, new 160 t stat, new water pump, new radiator, nothing out of the norm whatsoever.
God damned fans lol
A - you have dead fans, which you're about to find out
B, which is my problem - My fans weren't coming on until my car got up 3/4 on the temp gauge from standing still... after a lot of messing around I'm 99% sure this is attributed to either a bad oil sensor, or coolant temp sensor, or both in my case. While it's going to get fixed when I get my tune, I'm still going to replace those sensors.
I went through so much BS even thinking I had a bad head gasket lol.. i knew the fans were coming on so I didn't think anything of it, but they weren't coming on when they were supposed to. Same thing.. car runs perfect, no problems, no codes, runs cool when moving, never overheats, new 160 t stat, new water pump, new radiator, nothing out of the norm whatsoever.
God damned fans lol
Fan switch kits are under $100 and they're easy to install. Nice security for an LT1 car IMO
07-18-2012, 11:54 PM
#10
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had a similar concern with my 96 implala ss after installing a new rad. just disconnect the temp sensor at the front of the water pump with the engine running and both fans will come on in a short time. with temp sensor off I guess the computer thinks the temp is high and turns both fans on. this told me both fans worked. reattached the sensor and connected a code reader and let it idle and watched the temp and fans. passenger side fan turned on at 226 and turned off at 217. passenger side fan is the primary fan, driver side secondary and turns on at much higher temp. with the new rad my temp around town is about 195 with a 180 stat. so the fans hardly ever come on when driving .
07-19-2012, 09:16 AM
#11
had a similar concern with my 96 implala ss after installing a new rad. just disconnect the temp sensor at the front of the water pump with the engine running and both fans will come on in a short time. with temp sensor off I guess the computer thinks the temp is high and turns both fans on. this told me both fans worked. reattached the sensor and connected a code reader and let it idle and watched the temp and fans. passenger side fan turned on at 226 and turned off at 217. passenger side fan is the primary fan, driver side secondary and turns on at much higher temp. with the new rad my temp around town is about 195 with a 180 stat. so the fans hardly ever come on when driving .
07-19-2012, 08:09 PM
#12
The fans in 93-94 F-Bodies were set to come on in sequence. Driver side then passenger side. But that's for F-Bodies. In 95-97 F-Bodies, both fans come on at a low speed, then both go to high speed if additional cooling is required. Can't really say I know about B Bodies.
I put direct power to both fans and just my left side powers on (which I think is the high temp fan?) Whereas, the ride side fan won't come out when I give it direct power. Well, it actually sometimes does, but like 1 out of 30 times.
So I'm thinking its the fans that was causing the car to warm up? Because it took a while just for it to warm up and when it did, it slowly got up. About a 20 minutes or so driving around town it was just past halfways (220ish?) and slowly slowly kept getting hotter.
I assume thats the fans job to kick on by then and cool this lt1 down lol. I pray if I put new fans on it will keep cool. I'm also going to buy the slp manual fan switch.
07-19-2012, 08:22 PM
#13
Shbox can explain it better than me b/c I'm too lazy to do more than copy/paste the link right now lol.
http://shbox.com/1/4th_gen_tech2.html#cooling
Also, why spend $70 for http://www.slponline.com/view_product_site.asp?P=63011 when you can make your own for like $20 like I did?
Great write up for OBD 2.
http://shbox.com/1/fan_sw_diagram2.jpg
http://shbox.com/1/4th_gen_tech2.html#cooling
Also, why spend $70 for http://www.slponline.com/view_product_site.asp?P=63011 when you can make your own for like $20 like I did?
Great write up for OBD 2.
http://shbox.com/1/fan_sw_diagram2.jpg
07-19-2012, 11:40 PM
#14
Nice, thanks for that first link!
Now I did a manual fan switch but didn't work, which I think may be my problem. I thought its a DPDT switch which it does have 6 pins on the switch, but the front of the switch only has a On/Off position, no dual switch if I wanted high/low speeds. Who knows, I'll be getting new fans for sure and then double check everything.
Now I did a manual fan switch but didn't work, which I think may be my problem. I thought its a DPDT switch which it does have 6 pins on the switch, but the front of the switch only has a On/Off position, no dual switch if I wanted high/low speeds. Who knows, I'll be getting new fans for sure and then double check everything.
