cooling fans

[stoneymonk]

My primary fan works great when does the secondary fan kick on,or should they be working at the same time

[walterdude]

When the AC is on or if the engine gets REAL Fkn hot!!!
Tom....
Also once I forgot to connect the temp sensor,,, that will run both fans constantly.... If it is OBD1 and you jump the connector with a paper clip (like reading trouble codes) and turn on key both fans will run constantly....

[stoneymonk]

Thanks,I thought something was wrong.

[HayesPerformance]

You could burn a chip with a lower turn on temp,

If you have a 93' and older dohc, your alternator cooling fan doesn't kick on till the second fan does.

[jmgtp]

alternator cooling fan?

only fan on my alternator is the one bolted to it behind the pulley so as long as the alternator is spinning so is that fan.

I do remember there used to be some duct work on the back of my alterantor that showed up on the ground one day (literally it just fell off one day). Was there a fan in that?!

[55trucker]

Uhhhhhhhhhh.....actually, yes there was/is..the fan itself is located under the electrical control panel on the passenger side inner fenderwell, there is ducting that runs from that fan around to the backside of the regulator pack on the alternator. When the car is in motion forced air keeps the regulator cool, when the car is not in motion the engine temp has to rise to the point where the secondary fan engages and at the same time the alternator cooling fan also engages.

[jmgtp]

ah, I see now. I know what you're talking about now - I always assumed that fan was for the air injection on the exhaust manifolds.

[walterdude]

On my 93 Z34 there is no ducting that runs from the fenderwell.. The only Alt cooling "aid" is a duct that attaches to the back of the alternator. That duct drops straight down, sandwiched in between the engine and tranny and terminates there... The whole duct is only 8-10" (as a ques-timate) long... Is there a difference between GTP and Z34??? I wasn't aware of any...
I'm just curious.... I've swapped engines and the trans AND alternators and I KNOW I didn't have duct work there. NOT arguing,,, just curious.. You guys certainly know your LQ1s....
ThanxXX,,,
Tom

[pocket-rocket]

That little fan with a duct going to the alternator was on my 91. When I swapped in the 5 speed, I used the little duct that runs between the oil pan and transmission that is hooked on to the back of the alternator and removed that little fan. If I had to guess, I would say it would probably be only on auto equipped cars because there isn't much room in there for air to get in without the aid of a fan, and I know the 92 GTP my 5 speed came out of didn't have one, but had AIR injection in that spot. The output on the ECM that controls it probably hooks to the AIR injection on the 5 speed cars since the autos didn't have AIR injection.

[55trucker]

Actually.........I believe that 91 was the only year (such as mine)..to make use of the isolated alternator fan..
(but it might be there on a 92...tho I've personally never looked at one)

[pocket-rocket]

I know my 92 didn't get one from the factory, but then again, if it was an automatic trans car only thing, that would explain why my 92 doesn't have it as it came from the factory as a 5 speed, where as my 91 was an auto until I put a 284 in it. My 92 had the AIR injection pump in that spot. Well, before I removed the AIR pump anyways.

[jmgtp]

maybe this makes more sense to me now... since my car is 5sp and I had the air injection - until like pocket - pulled it out and welded the manifolds closed. There used to be a duct behind my alterantor but I don't recall it going to a fan.

[pocket-rocket]

What shape was the portion that went to the alternator? I know the duct that came to mine was round on the 91, and IIRC it was a plasticy (is that a word?) cloth type material. Then with the deal that goes in between the oil pan and trans on the 92 was rectangle, and a rubber/plastic material.

[jmgtp]

Honestly don't remember - I believe there was black plastic.

I'm currently on alternator #3. The original went at 90k due to the rear bearing seizing - I don't remember if this was before or after the ductwork broke, after would make sense since I believe the ducting cooled the rear bearing. The replacement Delco lasted 10k before I warrantied it out due to a bad voltage regulator (would spike up to 18v). The parts store claimed they were no longer able to get the Delco and they got me the cheapest alternator they had on the books and refunded the difference between the two. So now I have a cheapo (I think it was $60!) alternator for the past 20k without a single problem. It charges perfectly. I don't even remember what this thread started as.

[55trucker]

It's basically a round rubber/neoprene approx 2" dia. hose, there is a small bracket fastened to the backside of the alternator and the hose slips into the opening in the bracket and the end of the hose is directed on the regulator pack.