I have a 1986 Camaro IROC Z TPI which has the single fan and no fan switch. The fan motor, fan relay and relay pigtail have all be replaced as have the CTS. The fan still does not work. It use to work but stopped. Most solutions simply say to replace the single fan with a double from a donor car. However, one guy did recommend using a Hayden Thermostatic Fan Control to get the single fan to work and come on sooner. The part is $20 from Amazon, how would I go about installing this? I'm a complete and total electronics noob. Electronics is my biggest weakness. How would I install this thing? I know one part goes inside the radiator it looks like it comes with a relay and an inline fuse.

 

I've got one of these controllers but for dual fans. It has basic instructions on how to wire out all up. Pretty straight forward

 

You need a fan switch, or a temp probe of some sort.

Factory fan switch was in the pass side head between the #6 & #8 spark plugs. The wire to it was green w/ white stripe. I'd recommend seeing if you can get that whole system to work before going the aftermarket route.

 

That's the thing though, my car does not have a fan switch. There is nothing there and no green/white stripe wire. I have read on here that some single fan cars don't have a fan switch.

I've replaced everything on this fan, the fan motor, the relay, the relay pigtail and the CTS. It use to work but now it doesn't.



I don't see a fan switch.

 

Hayden 3647 uses a thru-radiator heat sensor switch and can be used for single or duel fan set-ups; wiring it in is pretty simple too.





https://www.ebay.com/itm/New-Engine-...c156e3da119ef2

 

I'm leaning towards that one since it's adjustable. I have a 180 degree thermostat in the car. The car stays at 180 on the highway. Only in traffic does it get hot. Coming on at 210 would be ideal.

 

Single fan cars have a fan switch. At least, in your year they did. The ECM they used in those didn't have enough brains left over, after dealing with all the important emissions-related functions, to work that one more thing.

Somebody probably put a set of heads in your car, with the one they put on the pass side having a plug in the hole where a switch would otherwise go. ALL SBC heads have that hole; on the driver's side, that same hole has the temp gauge sending unit in it. Then they tucked the wire up into the loom or something. Maybe cut it off.

Take out the plug, put in a fan switch. You might find that the heads you have are equipped with 1/2" pipe holes instead of the 3/8" pipe holes that the switch needs, in which case, go to Home Depot or equivalent and get a brass pipe bushing of those 2 sizes.

You can look at the fan relay plug. It has 2 small wires and 2 large ones. One of the small ones will be green w/ white stripe. Follow it. Put a new pigtail on it if it needs it when you find the end. Plug it in and you're done.

 

As far as I know my car has never had a fan switch. The fan worked up until a year ago and there has never been a fan switch there. As far as I know those are the stock 305 heads.

I'm pretty sure I read on here that 85 and 86 didn't have a fan switch. There seems to be little info on the fan set ups for our years even on this website. Which makes this difficult. I've replaced everything relating to the fan. The ECM was replaced a few years ago and as far as I know it still works. I've replaced the fan motor, the replay, the relay pigtail, the CTS and the CTS pig tail but the fan still won't come on.

Both of this threads mention that the 85 and 86 cars don't have a fan switch.

https://www.thirdgen.org/forums/cool...an-switch.html

https://www.thirdgen.org/forums/cool...an-switch.html

 

Not so: 85 and 86 TPI didn't have a fan switch,..Only the Carb with single fan did those years. The TPI fan control runs directly off the ECM. Probably 87 too,.... but that year the duel fan set-up ( if installed ) that required the head mounted fan switch for the HD (secondary) fan.

From the 85 shop manual: * "Switch" shown on schematic is the AC pressure switch; it tells the ECM to turn on the fan; it's not temp related in any way.




Vinscully50: If you "JUMP" the DARK GREEN / WHITE wire at the cooling fan relay with a ground wire while the key is turned to RUN the fan should come on. If it DOES than the ECM is suspect. ( ECM not sending switched ground as it should.) [ [b]CORRECTION: Could also be caused by the ECM temp sensor not working/reporting to the ECM so the ECM doesn't know to respond. ECM sensor is located @ the front of the TPI Intake.] If it does NOT then the relay/fan/wiring is suspect.

 

If you ground the AC pressure switch it'll turn on the fan too. At least in my 91 it did. Should work the same way. I've cut all that wiring out tho. I'm only using a fuel pump relay

 

Is this the high pressure switch? Where is it located? I think this might allow me to get two birds stoned at once if I fix it. Both my AC blowing cold and the fan coming on.

I know the low pressure switch is on the dryer and has the blue and green wires running to it. Where is this switch?

 

All you need to do is ground the "DK GRN/WHT" wires (335) when you want the fan(s) to come on. I use one of these:

https://smile.amazon.com/LITROK-Adju...%2C200&sr=8-11

 

But where is 335? I don't see any dark green/white wires.

 

Look at the schematic post 10 it’s there

 

I don't see any dark green/white striped wire anywhere under my hood. I've been looking but can't find one. Do you have a picture of where it is located?

 

Your fan relay might be mounted on the core support next to your battery.

 

I know where the relay is. I've replaced it before. I don't see any dark green/white wire running from the relay.

 

Have you grounded cavity b at the relay?
the wiring color might be different in your year vs the schematic.

 

It might be a different color. All my wires running from my relay are white or solid black.
If the relay pig tail is bad how can I tell? With a multimeter I get -630 ohms. I tried asking on a different car electrical forum but people told me they need to know the factory spec ohms to help me. I can't find that anywhere in the manual. I also read that there is suppose to be a 10 amp FP Fan fuse on the fuse box but I don't seem to have one.

Is there any way you can post pictures of cavity b, the wire and this AC pressure switch? I've a very visual oriented learner and it's easier for me to find/diagnose things when I can see them.

 

Look at the relay plug it should have the cavity letters on it. Sounds like the pigtail has been replaced. You should look back at the loom and retrace the wires as per schematic. I’m betting the connector was replaced with a acdelco pigtail at some point. I don’t recall I think there is a fan fuse in the fuse box.you will have to rely on others for pictures or get a fsm or use google.

 

Ill closer tomorrow morning. I'm sure a good portion of pigtails on this car have been replaced and use different color wiring. This is what makes it difficult to trace wiring sometimes and locate parts.
I've been trying to Google. A bunch of old threads come up on here but no pick of the AC fan pressure switch. Just the low pressure switch (which I replaced).

 

Ok. been going through this same issue on here lately. I have an 86 TPI (well was) until I started swapping. Anyway, there is multiple diagrams for this year. When you look through them, make sure up at the top that it tells you it is for your specific vehicle, (it will say F body, or fuel injected, carbed, s body, berlinetta, etc. etc.) When you are sure you have the correct one, it will start to make sense. People on here will give you one to another body style/same year and then get mad that your not "getting it", when in reality, they aren't. Take this link and go down to electrical, then cooling. Find your correct body style (this is for 86), and check it out. Then if you still don't want to mess with your factory seup-just take your Hayden kit (or whatever kind) and wire it up nice and simply. You will need a signal to turn it on (thermo fan switch or radiator probe). Your relay (like a switch). power and ground (for the fan circuit when the signal opens it). Your fuse, to keep the stuff safe and your fan pigtail to give it the juice. Should have everything in your kit. (except maybe your pigtail-but just reuse the factory one).
Here is the link to what you need:

http://92b4crs.tripod.com/86wiring/86wiringindex.html

 

I found the proper diagram this one.
http://92b4crs.tripod.com/86wiring/dia-pics/31-1.jpg

I like this forum but my biggest pet peeve with this forum versus any other car forum I've been on is that no one here ever post pictures or flatout tells the OP where the part is. Everyone just says look in the manual. I'm surprised the lack of pictures/Youtube videos that exist for problems with our cars. I'm guessing a lot of members of this forum are older. When I try searching for things on YouTube I really find anything third gen videos but a ton of Fourth Gen videos and sometimes they are similar enough that I can solve the problem other times no.

Anyway, It says there is a blue and black wire attached to it. I can not find anything under the hood that has a blue and black wire going it.
I've trying Googling for pictures of this Fan Pressure switch and not a single picture of it has ever been posted. I've trying searching the Autoparts stores and the only ones I can find are the low pressure switch from the drier and the high pressure switch on the back of the compressor.

I can't find this phantom ac pressure switch. Does anyone have a picture of it or can at least tell me where it is and what it looks like? What part is it next to or near?

 

Pretty sure it's on the metal AC line running down the pass side frame rail. Picture below is an 86 TPI.

 

No, people on here are giving EXACT drawings. John in RI already gave the correct drawing for the correct year, it is, in fact, the same drawing on the site you linked. It is the same drawing as in my Pontiac manual. There aren't hundreds of options for these cars, there are usually 3 or 4 engine options and that's it.

You may feel like we're being a little difficult because most people post then want someone to come to their house to fix it for them without doing any of the work on his/her own.

The fan pressure switch is SECONDARY to the ECM operating the fan, so if it is there, or isn't, is not the reason the fan isn't working.

 

I told you in the other thread where the part is. Did you look there? Did you take a picture of the hard line here so someone could point out where it is? WE'RE not there, there's only so much we can do to help and you said you have a manual, but you don't seem to be referring to it. I have all the manuals from 86-92 and I refer to them frequently instead of asking questions.

If you want to use the Hayden controller, follow the instructions that come with it. It should be a simple hookup, power to the unit, ground, temperature probe, and fan wire. Cut the original fan wires and connect the positive fan wire to the controller and the other wire to ground.
Wiring a fan really isn't electronics, it's wiring.

My feeling is that you need to start going through the troubleshooting process, IN THE MANUAL, or the instructions I provided in the other thread. With all the parts you have replaced plus the colors on the wires wrong say that someone has had their dirty d*** beaters in the car and the wiring is at fault. Until you start checking wires you may never figure it out.

Have you even checked for power at the relay terminal from the fusable link?

 

Yea, your right on, on this thread. Never meant it to come across like I was knocking John's help (he's always helpful and polite, i like his threads). But there is too many people here lately giving wrong details and or saying you have this and that part, when the year in question doesn't. Sooo, I was trying to give him his own link to look for himself AND to be able to distinguish which one to use on his own. I did say there was 3 or 4 (not 100's). I had to figure it out on my own after being tired and frustrated with the look for yourself replies. They would be arrogant about there help. I'm not repeating myself-(God had spoken) said one. lol give me a break.
I don't think anyone on here looking for answers, is really looking for someone to come to their house and do the work for them, either. Obviously some on here do think so.
I don't have a huge amount of experience on these yet, but I'm willing to share without flaming someone to a hardened charcoaled piece of ash (with a light hint of burnt hair).
3rdgenzroc

 

Sorry for the long awaited reply. Me and a buddy who is a dealership tech did some poking around at the stock system and couldn't find a short. We did wire in the fan controller. Took us a little longer due to my car's already hack job wiring but we got it working.

Good News: The fan works again.

Bad News: The fan is coming on two early even after adjusting the setting screw like the directions say. The fan seems to be coming on at 180 degrees vs 210. We adjusted the screw 3/4 turn like the directions said but it still comes on too early. At least it is not coming on at 90. I'll play around with it some more tomorrow. It feels good to have a working fan again.

 

Glad to hear the fan is turning !!!

As 'fate' would have it,..... today I found the Hayden instructions while cleaning up in the garage a bit this afternoon.

While Looking over the instructions a fine detail caught my eye, something I've recommended to others in the past. So; one more piece of advise,... don't blindly believe what the temp gauge is telling you. Best if you KNOW what temp thermostat is installed,... but the 'best' way to initially set-up the fan controller is:

I prefer this method over using a infrared hand-held. Thermostats ( in MY experience ) are usually a better way to judge coolant temps rather than relying on a Temp gauge to be accurate. ThirdGen temp gauges have a very (well-deserved) bad reputation !!

The Hayden will probably still need some fine adjustment. You'll know after driving the car for a week or so which way to turn the screw. Keep any more adjustments VERY minimal and allow enough drive time to really understand how it's acting before making any additional adjustments.

* If you splice the GREEN wire to the GREEN wire on your AC controller; turning on the AC *should* kick the fan on; just a way to control the fans manually. Disclaimer: (GREEN wire = +voltage when AC is on my car, verify 12 volts when AC is on in your car )

For future readers:

 

Thank you John. I'll play around with it more during the week. The fan controller is spliced into the AC compressor and comes on as soon as the AC or heater is switched on.

You're instructors were better than mine. Mine were a bad printed where parts of the paragraphs were really dark and look printed over.

 

My 1986 TPI didnt have that fan switch either drove myself and the Mechanic nut looking for it !