Radiator Fan Issue

[ZBOOST]

Hey guys,

The engine in our 35 runs so smooth and feels like new so it was a surprise to me that one hot day on parra road the temp needle started to spike where it shouldnt to the point where i almost had to pull over. This was frustrating so yesterday i pulled up in the drive way and let it run on 3000rpm untill it started to get hot.. i jumped under the hood to find that only one of the 2 thermo fans were running. The passenger side fan was not working with the temp gauge at 3/4. Can anyone help me fix this problem? is there a fuse for it somewhere or anything i can trouble shoot to get it working again.

Cheers

[scotty nm35]

I would suggest bleeding the coolant system first, they can be quite hard to bleed and only a cup full missing can cause an airlock and overheating, similar to what is occurring to your car.

[ZBOOST]

Thanks, will do ! still doesnt explain why the 2nd thermo has not kicked in by the 3/4 mark tho...

[sonicii]

I think you probably have a fan issue too. With only 1 fan running, it will be less than 1/2 as effective as both fans. Which will explain the overheating.

[Daleo]

Didn't Alex discover that the PNM35 fans switched on very late (98 deg), and was able to lower the switch point to around 88-90 deg with his Uprev?

I wouldn't be surprised if this isn't a similar issue; along with improper bleeding.

[PN-Mad]

Stock temp switch for the fans is 100 degrees. Uprev can set the temp to whatever ou choose.

Normally the fans won't switch on unless stuck in traffic, or idling for extended periods.

Look and the connections first, they are plugged in at the back of the fan. You can test by applying 12 volts to the fan, if no good then get a new set from wreckers.

But i agree, make sure no leaks, and correctly bled too.

[ZBOOST]

Thanks, I have checked plugs.. There all secure, hooking up direct 12v is a great idea to see what's happening with the second fan. I will also make sure it's bled properly. Thanks.

[Deep Dish V35]

the fan motors can burn out...

95 degrees? is that at the rad input or thermostat?

my car always runs at 2/3 to 3/4 on the gauge, replaced everything except for the gauge itself. installed my own thermo fan setup with a 78 degree switch between the rad output and thermostat... 78 degrees is at the 2/3 to 3/4 mark on the gauge, which was checked as being 78 degrees with a scantool aswell.

[t5iv]

Really I'm always sitting at half way on the gauge.

[sonicii]

Mine usually sits just under 1/2 on the gauge, it is probably smack on 1/2 when the fans kick in.