carb cooling fan

[shoskins]

humper99 had said in a earlier post that

The fan mounted to the firewall is the carb cooling fan. After 10 minutes of driving it should kick on after the key is turned off. Without this functioning you will experience vapor lock in the carb and develop a hot start problem especially as spring and summer approach.

I going down to troubleshoot my "cooling fan" right now. The only thing I could find in my haynes manual is the wiring diagram on page 12-22 and a bad drawing of "Typical relay location details" page 12-3. Its the only technical refrence I have for now. I'll post later with the results and may beg for help. The the 60 runs great just bugs me that the fans not kicking on.

 

[oldgrey60]

That's partly right the cooling fan also cools the the intake/ exhaust manifolds. Wthout the cooling after the engine is shut down you will warp the manifolds sooner than they already do.

I would start with your manifold temp sensor mounted on a bracket under the exhaust manifold toward th rear firewall. A single wire/ plug goes to it. If it is good there is a cooling fan relay in the drivers side compartment behind the kick panel. this controls the time sequence of the cooling fan. There is also a fuse that powers the fan, should be marked as STOP HORN.

I have not found a ohm test yet in the FSM for testing the sensor. I will look to see if I can find it.

 

[surfpig]

I did this. Mind you, it's a FJ55, but same thing. I also have that thermonuclear exhaust manifold, which can warp 'n crack manifolds like nobody's business, so cooling is important (shoulda just got a header...). Anyway, works much better, weather's not warm enough yet to evaluate hot starts.

 

[JBBenson]

If you ground the wire going to the temp sensor, shouldn't the fan come on? (ignition off?)

I have replaced almost everything in my cooling fan circuit, still doesnt work.

 

[oldgrey60]

How about the fan itself? Check to see if you have open winding. may be bad? Better yet 12v + & - direct from battery to check operation.

 

[JBBenson]

My fan works with direct battery power.

Have replaced fusible links, and all relays. It worked once, but never again.

My only option is to follow every wire and see if there is a break somewhere.

Unless someone has a better idea?

 

[Mr Buckfast]

which relay?

I've been having difficulty with my cooling fan as well - it doesn't engage after the engine's been running.

I did the ground trick and discovered that the fan is operational. The sensor was recently replaced - so let's talk relay...

Looking at the sor website, they advertise two relays - one (which I've located) is box-shaped and houses what looks like a large computer chip - these run about $100 used. The second type of relay pictured is your more typical silver cylinder-shaped variety (around $13 on sor).

What's my next step in rectifying the issue? thanks.

 

[surfpig]

Really: just get an aftermarket adjustable fan controller, wire it in, and be done with it. I've even got an auxilliary circiut for an additional fan now. 50 bucks. Done.

 

[Mr Buckfast]

not a bad idea, but...

...I'd still like to see if I can resolve the problem by putting in a new relay and, to do that, I need to know which relay to switch out.

Fired up the rig for the first time in over a week - let it run for 20 minutes, and the same thing happened - fan didn't come on after shutting the rig off. Furthermore, after a ten minute intermission, the car wouldn't start back up until given an even longer break and a propped hood.

I think it's clear that I have that vapor issue going on that's making the warm starts difficult.

In terms of relays, I did notice that there is a silver cylinder variety located directly under the boxed computer chip (marked "engine cooling relay") - is there a chance that it is this cylinder relay, which is set off from the "panel" of relays, is the one I'm hunting for.

I desperately want to resolve this issue so I may know that if this deal with the carb blower is creating my difficult warm starts.

 

[surfpig]

I have a picture of my original fan controller, I don't know if they're the same on a 55 vs. a 60... (but I can't resize it here at work! i can email it to you if you want...)
20 minutes might not be long enough for things to heat up, even my new setup doesn't kick on all the time.
You might try insulating your fuel lines, see if that helps, too. These little gremlins are annoying...

 

[soggy60]

90% of the cooling fan problem is the skimpy little (bule ? green ? ) wire from the harness under the fan that goes to a connector, with an equally skimpy wire from the connector to the sensor.
The skimpy wire is cooked to death.

Another small probability cause: bolts that hold plate that sensor is screwed into are kinda rusty; poor electrical connection.

And still another little seen cause: bad connections at the fan relay: it's behind the LEFT kick panel...(the side that ocassionally leaks when it rains)
It's not shown correctly in the above or it's for a different model 60 - mine ( Nov 85 built) is behind the left kickpanel . . .

the box ( item 10 in way above pic) behind the right kick panel 'read's the sensor and controls the relay mentioned above.

You can test the sensor; removing it to do the test 'correctly' is the tough part.
With ohmmeter (red to sensor post, black to sensor housing) : should see many thousand ohm.
With cigarette lighter ( wood match) , GENTLY heat sensor : resistance should fall - alot, but not to zero ( doen to 1000 or less ohms)

HTH

Pete

 

[JBBenson]

You mean if I bypass the wire to the sensor, (at the harness) and go to ground, the fan should blow, right? If everything else is there?

 

[Mr Buckfast]

Victory Is Mine!

I'm not the originator of this strand - but I described difficulties I was experiencing in this and an earlier strand.

After sucking up all the advice I could, I purchased a new relay (of the #2 variety) and, after firing up the rig for 45 minutes and shutting it off, the fan came on!

Thanks for the advice from those on this strand and my previous - bring on the warm starts!

 

[Mr Buckfast]

Spoke too fast?

Well, I wrote the last message after the fan kicked in and as I was giving it time to do it's thing before attempting a restart (with the hope that my vapor lock/warm start issues were forever gone).

Rig did not start.

Quick story -- bought car a month ago and drove from San Diego to Seattle. The whole time the cooling fan never engaged. Twice on the trip, I experienced a situation where I would go to do a warm start, and absolutely NOTHING - perhaps a singular mild click, but no noise coming from the starter. After a loooooong break, rig would fire up. Mind you, this is days after having a rebuilt starter professionally installed.

This just happened again, and I can't help but think, even though it seems far-fetched, that this scenario is completely unrelated to the success I just experienced in replacing the relay.

I am at a sad, sad loss for what to search for next. Please, tell me it's simple?

 

[surfpig]

I'm not the originator of this strand - but I described difficulties I was experiencing in this and an earlier strand.

After sucking up all the advice I could, I purchased a new relay (of the #2 variety) and, after firing up the rig for 45 minutes and shutting it off, the fan came on!

Thanks for the advice from those on this strand and my previous - bring on the warm starts!

(mine still stumbles just a bit on warm starts...)

 

[PabloCruise]

How about the fan itself? Check to see if you have open winding. may be bad? Better yet 12v + & - direct from battery to check operation.

I was going to power the fan directly when I discovered a piece of pea gravel lodged in the squirrel cage of the fan...

 

[Mr Buckfast]

quick thought - potential solution?

perhaps my dinking around with the relays put my ignition relay to eternal rest. I was pulling it out and swapping it around before I figured out which relay was for the cooling fan.

It's as if the ignition process doesn't even get to the starter, so I'm going to pray that this is a $15.00 solution and purchase an ignition relay tomorrow.

Comments on this line of logic? Thanks so much.