Engine running hot.

124JOE · Post by **124JOE** » Sun Oct 23, 2011 6:41 pm

no question you need a fan

rlux4 · Post by **rlux4** » Sun Oct 23, 2011 9:45 pm

Before you buy a new fan you should try to run power and ground straight to the fan without going through the temp switch. You'd need standard male and a female bullet terminals, unplug the first connector (it's a dual terminal) off the fan and plug 12V and ground into them. This direct connection will tell you if the fan works. The male end on the fan side of the connector is power, the female is ground.
Ron

kiznarsh · Post by **kiznarsh** » Fri Oct 28, 2011 2:30 am

Alright folks, the saga continues...

I ended up buying a new fan and just replaced it tonight. The connector on it didn't match the stock connector, so I cut it off and also cut off a few inches from the stock fan cabling, then I used butt splices to attach the stock connector to the wires coming off the new fan. I checked continuity across this setup and everything was good.

After reconnecting everything and getting the engine above 190 (and a little over 200), the fan still doesn't come on. I checked the voltage across the terminals on the connector that hooks up to the fan connector and I was getting ~11.5V, so the switch is still working. Like an earlier post, I plugged in just the positive wire to the fan connector and used another wire from the negative terminal on the fan connector to the ground pod on the inner fender on the driver's side (I checked all possible terminals and focused on the largest wire going to the pod since I understand that's the ground for the fan)...but still nothing.

Just to make sure all the terminals on that ground pod are good, I checked the voltage between the positive terminal on the connector coming off the radiator and all terminals on the pod, and they all read ~11.5V.

So if I'm feeding 11.5V to the fan, there's continuity across the spliced connector that I just made, and I have a good ground, then I don't understand why I'm having problems. I don't have a 12V battery to directly hook up the new fan, so it's possible this fan is bad too, but it's unlikely. Now I'm starting to think my original fan was fine (potentially an expensive mistake) and I have another issue somewhere...

Now what?

Thanks.

124JOE · Post by **124JOE** » Fri Oct 28, 2011 10:00 am

im at a loss
but you can use the pos post on the back of the alt for power test,just be carfull

aj81spider · Post by **aj81spider** » Fri Oct 28, 2011 12:25 pm

You have 11.5 volts at the connector with no load. There may be a lot of resistance in that part of the circuit, so that when loaded the voltage drops. I would do the following:

> Make sure the fan is good - get +12 from somewhere besides that connector and ground to the chassis.

> If the fan is good then buzz out the resistance of that wire - trace it back through until you find where the extra resistance is being added.

If you can, measure the voltage when the fan is switched on but not running. My guess is that it falls to a lot less than 11.5.

majicwrench · Post by **majicwrench** » Fri Oct 28, 2011 12:49 pm

You have a 12v battery in the car, use it for testing.

kiznarsh · Post by **kiznarsh** » Fri Oct 28, 2011 1:50 pm

majicwrench wrote:You have a 12v battery in the car, use it for testing.

Touche.

Yeah I definitely need to verify the fan works. And if it does, then something's causing a huge voltage drop...

TX82FIAT · Post by **TX82FIAT** » Fri Oct 28, 2011 4:00 pm

As stated earlier. if you use the back of the alternator because it is in close proximity please be careful. Embarrased to say I have a couple burn marks on my wrist for being stupid not once but twice when checking things out from the alternator post.

kiznarsh · Post by **kiznarsh** » Mon Oct 31, 2011 1:07 am

Weekend update:

I verified my fan works by hooking it directly to the battery, so good news there.

Later on I jumpered the wires coming off the radiator switch and hooked everything else up and read 10.5 V going to the fan (fan wasn't spinning). Then I ran a wire from the positive battery post to the fan with the ground hooked up normally and the fan worked while reading 12.6 V, so clearly there's a voltage drop somewhere.

I know the switch works, the fan works, and I have a good ground. Now I need to focus on the positive wire going to the connector that hooks up to the fan connector. I didn't get a chance to look underneath and trace that wire but am I right in assuming the following:

The big green cable coming off the positive battery post goes through the firewall and to the alternator, and then there's another positive wire that goes from the alternator to either the connector that attaches to the fan or to the connector that attaches to the radiator switch. Does that sound right?

Thanks again.

digitech · Post by **digitech** » Mon Oct 31, 2011 8:23 am

No positive wire to rad switch, just ground.

kiznarsh · Post by **kiznarsh** » Fri Nov 04, 2011 2:34 am

Finally!

After downloading Brad Artigue's awesome wiring diagram, reviewing it, and remembering people mentioning the horn, I rushed home and was hoping my horn wouldn't work...it didn't. I swapped the #10 fuse and bam! Horn works! Turned on the car, got it above 190 and the sweet, sweet humming sound of the fan both scared and excited me at the same time...

This new fan from IAP seems like it spins at a higher RPM and is causing the housing to vibrate a lot more. This weekend I'm going to double check that everything's tight but it's definitely louder. Not that I'm going to swap it out but there's definitely no issues hearing the fan come on.

Thanks again for everyone's help and insight!

Engine running hot.

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