Relay for electric fan - The 1947 - Present Chevrolet & GMC Truck Message Board Network

profe56 · 01-21-2014, 02:19 PM

Hi folks:
yesterday I had problem, the electric fan did not work, I think the relay is not working properly, because I noticed this, days ago.
I you can tell me where can I find a good one, please tell me
Thanks

**LockDoc** · 01-21-2014, 03:27 PM

Quote:

Originally Posted by profe56

Hi folks:
yesterday I had problem, the electric fan did not work, I think the relay is not working properly, because I noticed this, days ago.

Cooling fan for radiator or heater fan?

I you can tell me where can I find a good one, please tell me
Thanks

Fan or relay? More information would really help...

LockDoc

**VetteVet** · 01-21-2014, 03:41 PM

Turn the key on with engine off. Check for 12 volts on the 85 and 86 terminals. You should get 12 volts on the hot side and nothing on the grounded side, because the heat sensor in the block is not grounding. After you determine which terminal is hot then ground the other terminal and listen for the relay to click. Use Caution because this should start the fan unless you unplug the fan harness.

If the relay clicks check for 12 volts between the 87 terminal and ground while the relay is engaged. If you get voltage then the fan is probably shot.

You can hot wire the fan with a ground to one wire and a hot wire to the other and the fan should run. You can also check the fan windings with an ohmmeter by checking continuity between the fan wires. If you get infinity then the fan windings are open.

Here's a diagram.

Name: hppp_0801_26_z+improved_pontiac_cooling_system+diagram.jpg
Views: 310
Size: 28.2 KB

Name: hppp_0801_26_z+improved_pontiac_cooling_system+diagram.jpg
Views: 310
Size: 28.2 KB

Yes cooling fan or heater fan?

profe56 · 01-23-2014, 12:04 AM

Sorry for the delay:
Relay.
I think I need new one. some times radiator is not really hot and turns on and some times is over the temparature and doesn't turn on. And the day I did the question my truck was overheating.

Zable49 · 01-23-2014, 12:47 AM

It might be your relay which you can get at any autoparts store. But it also might be your inline thermostat. Something else you can do is run the optional override switch so if you notice that your truck is running high, you can kick it in so you dont overheat. I've gotten bad thermostats out of the box. Its just a sensor that grounds out when it hits a certain temp.

profe56 · 01-23-2014, 12:51 AM

thanks

Andy4639 · 01-23-2014, 02:05 AM

You can get 30amp relays just about any parts store and radio shack. Wal mart even carries them.

Jb70c10 · 01-23-2014, 05:25 AM

For what it's worth; I've had good luck with relays made by painless but they are a little pricey. I think I have to agree with the bad thermostat theory in your case though.....

MARKDTN · 01-23-2014, 08:12 AM

Quote:

Originally Posted by Jb70c10

For what it's worth; I've had good luck with relays made by painless but they are a little pricey. I think I have to agree with the bad thermostat theory in your case though.....

I don't think Painless makes relays. For this style you really want a Bosch or Hella brand. I like the late '80s-'90s Delco oval relays also, they really hold up well but you would have to change your holder for that.

Jb70c10 · 01-23-2014, 01:33 PM

http://www.summitracing.com/search/p...%20fan%20relay

I used kit from painless. Here is a link to some options
from painless I pulled up by doing a search on summit racing web site. May or may not be what you need. You may have to cut and paste the link into your browser to make it work, sorry. Good luck!!!

MARKDTN · 01-23-2014, 06:40 PM

Quote:

Originally Posted by Jb70c10

http://www.summitracing.com/search/p...%20fan%20relay

I used kit from painless. Here is a link to some options
from painless I pulled up by doing a search on summit racing web site. May or may not be what you need. You may have to cut and paste the link into your browser to make it work, sorry. Good luck!!!

That link shows a Hella relay on a Painless harness. That would be OK. I would just stay away from the generic/offshore 5-prong relays-especially for HD service like a fan and mounted on the engine compartment.

profe56 · 02-02-2014, 02:25 AM

is the inline thermostat.You think is possible to buy it separate of a set. the set I have I bought it at O reilly. Today my friend mechanic fix it and is working when the engine is turned on and off when is turned off.
Is the inline thermostat incrusted in the honeycomb of the radiator?

piecesparts · 02-02-2014, 02:49 AM

Get the heavy duty relays out of the 73 to 87 Chevy trucks that they used on the heaters. They stand up to just about anything and are plentiful throughout the salvage yards and parts stores.

01-21-2014, 02:19 PM	#1
profe56 Registered User Join Date: Nov 2008 Location: Chula Vista California Posts: 526	Relay for electric fan Hi folks: yesterday I had problem, the electric fan did not work, I think the relay is not working properly, because I noticed this, days ago. I you can tell me where can I find a good one, please tell me Thanks

01-21-2014, 03:41 PM	#3
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,709	Re: Relay for electric fan Turn the key on with engine off. Check for 12 volts on the 85 and 86 terminals. You should get 12 volts on the hot side and nothing on the grounded side, because the heat sensor in the block is not grounding. After you determine which terminal is hot then ground the other terminal and listen for the relay to click. Use Caution because this should start the fan unless you unplug the fan harness. If the relay clicks check for 12 volts between the 87 terminal and ground while the relay is engaged. If you get voltage then the fan is probably shot. You can hot wire the fan with a ground to one wire and a hot wire to the other and the fan should run. You can also check the fan windings with an ohmmeter by checking continuity between the fan wires. If you get infinity then the fan windings are open. Here's a diagram. Yes cooling fan or heater fan? __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

01-23-2014, 12:04 AM	#4
profe56 Registered User Join Date: Nov 2008 Location: Chula Vista California Posts: 526	Re: Relay for electric fan Sorry for the delay: Relay. I think I need new one. some times radiator is not really hot and turns on and some times is over the temparature and doesn't turn on. And the day I did the question my truck was overheating.

01-23-2014, 12:47 AM	#5
Zable49 Registered User Join Date: Jun 2007 Location: Lacey, Wa Posts: 181	Re: Relay for electric fan It might be your relay which you can get at any autoparts store. But it also might be your inline thermostat. Something else you can do is run the optional override switch so if you notice that your truck is running high, you can kick it in so you dont overheat. I've gotten bad thermostats out of the box. Its just a sensor that grounds out when it hits a certain temp. __________________ 1970 C20 Camper Special SBC350 / TH350 '84 C20 Front Disc Brakes/Control Arms

01-23-2014, 12:51 AM	#6
profe56 Registered User Join Date: Nov 2008 Location: Chula Vista California Posts: 526	Re: Relay for electric fan thanks

01-23-2014, 02:05 AM	#7
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: Relay for electric fan You can get 30amp relays just about any parts store and radio shack. Wal mart even carries them. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

01-23-2014, 05:25 AM	#8
Jb70c10 Registered User Join Date: Jan 2014 Location: TX Posts: 181	Re: Relay for electric fan For what it's worth; I've had good luck with relays made by painless but they are a little pricey. I think I have to agree with the bad thermostat theory in your case though.....

01-23-2014, 01:33 PM	#10
Jb70c10 Registered User Join Date: Jan 2014 Location: TX Posts: 181	Re: Relay for electric fan http://www.summitracing.com/search/p...%20fan%20relay I used kit from painless. Here is a link to some options from painless I pulled up by doing a search on summit racing web site. May or may not be what you need. You may have to cut and paste the link into your browser to make it work, sorry. Good luck!!!

02-02-2014, 02:25 AM	#12
profe56 Registered User Join Date: Nov 2008 Location: Chula Vista California Posts: 526	Re: Relay for electric fan is the inline thermostat.You think is possible to buy it separate of a set. the set I have I bought it at O reilly. Today my friend mechanic fix it and is working when the engine is turned on and off when is turned off. Is the inline thermostat incrusted in the honeycomb of the radiator?

02-02-2014, 02:49 AM	#13
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Relay for electric fan Get the heavy duty relays out of the 73 to 87 Chevy trucks that they used on the heaters. They stand up to just about anything and are plentiful throughout the salvage yards and parts stores. __________________ Frank



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