Hawkman978

My car is the 3.4L V6, and its fan will not turn on. I have changed the thermostat, replaced radiator fluid. But when I turn on the AC in my car the fan still won't start. The car will warm up and not stop heating up causing the engine to over heat. I have also checked the oil at running temp. Doesn't appear to be a blown head gasket. I have also checked the switch next to the thermostat and it appears to be working. been trying to fix for three months now at a total loss. Any advice will help.

Injuneer

You can't really tell if the coolant temp sensor (it's not a "switch") is working by looking at it. If it is seriously defective, open or shorted circuit, you will get trouble codes DTC 14 or 15. Have you scanned the PCM for codes?

If the sensor is simply inaccurate, use this to test the sensor, and the wiring to it:

4th Gen LT1 F-body Tech Articles

The fan is turned on when the PCM sends a ground to the cooling fan relay in the underhood fuse box. The relay is provided with 12V power via fuse #6 in the underhood box. Check that fuse. Verify that (key on) there is 12V at the brown wire on the cooling fan relay.

The fan gets 12V power directly from the battery "+" box, via a "fusible link". It's possible the fusible link is blown. Go to the fan relay. Measure the voltage at the terminal with the red wire attached (key does no have to be on, power is always supplied). If you have 12V at the red wire, move to the fan connector, and measure the resistance between a chassis ground and the black wire in the connector (connector off fan). Should be close to 0 V.

This is what the fusible links look like:

Courtesy of Shoebox

http://shbox.com/1/fusible.jpg

Injuneer

Now I find I've already answered this question once before, a few days ago. If you didn't feel my answer was adequate, or you didn't understand something, all you had to do was add on to that thread.

Starting a new thread when you have already received responses on an earlier thread on the same subject is not a good idea, and wastes the time of people who are trying to help you.

https://www.camaroz28.com/forums/gen...urning-883771/

Fred/MODERATOR

Hawkman978

I had accidentally left out the size of the engine and what you posted was for the wrong size engine, therefore the information was not correct. I apologise for the inconvenience.

jfitzmo

Hey Fred. When you get a few minutes, can you add to your advice from way back in 2016 to a guy named Hawkman.

Background:
-'95 3.4L 127,000 miles, just got running again after 13+ yrs - long story. Had to replace all injectors, new tank (basically), new pump, new regulator, shined up rail nicely, & fresh synth oil/filter. Runs good, could prolly use some new vacuum rubber. I tore apart all brakes, cleaned/painted whole front under-carriage but still needs lot o' rust clean-up & lithium/silicone treatment underneath.
--Heavily flushed (3x). Firstly, no treatment of: engine, htr core, & radiator then, with left over evaporust, diluted a bit, and, finally, a long comprehensive flush with prestone.
--New cooling sensor & thermostat
--Per your advice; fuse #6 checked/fine, all fusible link's at + battery box/ bank have 12+ volts on other side of shrink wrap which I assume is where fuses are located with key to accessory, 12v at red wire in underhood fuse box, & finally, resistance between a chassis ground and the black wire in the connector is 0 ohms.

Also, I have connected GaryDoug's Scan9495 and show no relative prior or current codes, just an old IAC valve code which I replaced weeks ago. Interestingly, I can manually use "actuator/fan on" function in gary's app and watch the temp rapidly drop to normal or even better. If I could just keep the fan on always (switched, of course) only while engine's running, I can concentrate on tweaking this 13 yr dormant beast.

Interestingly, there's a "Cam signal missing" flickering at the bottom right Status area of app. I'm guessing the Cam sensor may need replacing? Anyway, any advice will be well appreciated.

Injuneer

Is your problem EXACTLY the same as the previous guy's problem? Tagging a new member's post onto an old (and in this case unsuccessful) thread often turns up differences in the symptoms, attempted cures and vehicle specifications.

I really don’t know much about the 3.4L V6. Does it have one fan or two (depending on whether it has A/C)? What are the fan on/off temps? Is #6 the correct fuse related to the fan?

In your Scan9495 screen shot appears the coolant temp is 192°F, and none of the A/C commands are green. Pretty sure the fan activation temp (A/C off) is way higher than 192°.

jfitzmo

I never said our problem was 'exactly' the same, hence the reason I provided my own comprehensive info and screen grab. Your advice for both of us, given his assessment of his problem (symptoms & vehicle specs) and mine were spot-on. Your advice for a 'cure' was simply universal troubleshooting steps for a non-working fan.
Anyway, I thought all 3.4 piece's of ****e had a single fan. The a/c isn't a priority yet, unless the fan depends on it of course. I know the a/c relies on a working fan but I didn't think the fan relied on working a/c. Ftr, the a/c system hasn't had any pieces removed so no hard system breach. I remember flicking on the a/c the day I got it running a few weeks ago. Compressor never clutched but hopefully it still had a decent seal. Ironically, I was going to evacuate after the fan was functioning correctly. Hopefully, it will hold a vacuum.

What are the fan on/off temps?
"As I said, I can manually use "actuator/fan on" function in gary's app and watch the temp rapidly drop to normal or even better."

Is #6 the correct fuse related to the fan?
"Per your advice; fuse #6 checked/fine"

Pretty sure the fan activation temp (A/C off) is way higher than 192°.
That particular screen grab was one of many. I let the the temp reach 220-230 a few different times. That's why I manually activated it.

I've surfed for weeks in the internet ghost town's of Camaro forums for experts. After a lengthy assessment of your post's, I determined that you consistently demonstrated a large cache of universal knowledge of fbody's. That's why I chose you. If you know someone else that you could recommend for 3.4's, please let me know.

Injuneer

Good luck with that attitude. Getting irritated because I asked questions to insure I understood your specifics of YOUR problem??? That's the problem you created when you tacked your problem on someone else’s, particularly one that isn’t going very well. I've wasted my time too often in the past going down that road.

I only try to help with the 3.4L V6 here because no one else here seems to want to. I made it quite clear I didn’t know some important facts about the 3.4L V6, and asked you to fill in the blanks. I could have taken some time to review the 1995 factory service manual for V6 info, but so could you. I guess a simple response like “my car has one fan” was asking too much. Or “I don’t know the fan on/off temperatures”. My reference to fuse #6 was made when I didn’t know the engine the thread originator had, and provided the LT1 info. He only edited his original thread, and started a new thread with the engine info when I pointed out he needed to provide his engine info.

We have a few people who are asking for help with the V6’s, but seems none of them want to return the favor.

I'll delete my unsatisfactory response, and this one as well, on Monday.

jfitzmo

"I asked questions to insure [sic] I understood your specifics of YOUR problem???" "..tacked your problem on someone else’s.." ? My problems were autonomously explained very clearly as MY problems also, so what. I only used his as an example because of the exact similarities. My fan doesn't work right. Period. I included everything you needed in my original post to jump to another step like maybe the ECM or a bad ground somewhere else. My irritation was because you had ALL the information you really needed and you chose to focus on petty stuff and still are. And, ftr, you began your first response with condescension and snarky attitude, not me. If you don't have the knowledge with 3.4's that's fine but I wasn't asking you to reinvent the wheel old timer. Switches, fuses, sensors, grounds, electrons, etc. all operate on mostly universal principles. You gave whatshisname troubleshooting steps 1-6 with way less information than I provided. I'm sorry you couldn't help and I'm sorry you don't have more support.

Injuneer

When your first attempt fails, switch it to a personal attack…. very mature. LOL

Grow up.

Closing.

jfitzmo

Well, you pissed me off Fred. The "LOL" you ended with kinda causes some "maturity" dissonance, btw. Just saying. Despite your incredible knowledge base and obvious post-grad intellect, your bedside manner needs some tweaking doc.

I read probably 50% of all your posts on several forums (I'm retired also). Your points to posters only interested in a "quick fix" and failure to follow up, especially after investing more effort/time in their issue than they did, is true of course but it's also the nature of help forums. I've found several threads of yours that rightfully chastise people for incomplete data. Some talk about the 3.4L and one thread showed that you already knew about single fan configuration among other things yet you chastised me. Many of them had 5% of the information I provided you and yet you quickly provided some of these guy's with 10x more information than they deserved.

I feel you may have a bit of poster ptsd now. All of the Camaro forums now are pretty much at their end of life it seems so I suppose new users are all going to be wham bam thank you m'ammers. Frankly, posters putting little leg work on the subject or issue before posting was my peeve. For my problem(s), I download every relevant document I can find from a million different web sites. I copy/paste so much information I have to develop Outlines. Sometimes I even make my own flow charts and even a Venn diagram occasionally. I talk to mechanics, auto part guys, vocational instructors at the local high school & the University-anyone that I think may provide anything useful.

The treasure trove of your post's gave me some good ideas for my fan problem so I really didn't need the live version of you, lol. All fixed. But, thanks nonetheless. At least your legacy will live on ole' timer.

Injuneer

Hopefully you remember that you set the tone and terms of this relationship when you intentionally, deceptively, and dishonestly posted your 3.4L V6 issues in the LT1 Scan9495 thread, without identifying your engine. Exactly the kind of behavior that would cause the “poster ptsd” that you have determined I am suffering from. Yes, I get very frustrated with wasting my time on people that can’t be bothered to give me all the facts up front, nor to answer questions intended to flesh out the topic. I really should have stuck with my “I'm done with this.” closure to the LT1 posts. Not sure why I even attempted to get past your annoying, condescending attitude and try to help in the thread.

In an effort to insure (see later) you weren’t holding back facts, and playing your little game again, I asked you to clarify a few points. And you still wouldn’t cooperate. If I made a comment in another thread about a V6 having a single fan, it was probably because I looked it up in the appropriate factory service manual. And I freely admit I do not remember each and every fact I have posted in 70,000+ responses. All you had to do is say “yes”…. not too much of an effort.

EDIT: Actually, what I said in that thread was “The 3.4L V6 has a single fan setup, correct?”. Not sure that indicates I know for a fact the V6 only has one fan. And I asked the thread starter to confirm one fan, just as I asked you. And he didn’t respond, just as you didn’t. Might want to read the posts more carefully.

”insure” per Merriam-Webster:

https://www.merriam-webster.com/thesaurus/insure