overheating

ds475 · 08-31-2003, 11:59 PM

recently i noticed my radiator fans no longer run after i turn off the engine, and i don't believe they even run at all when the engine's running. it just happened today, and i was wondering if there is a common problem with radiator fans? or what should i try?

scheistermeiste · 09-01-2003, 12:29 AM

Bad thermo fans switch if they dont come one at all. what happens when you turn the ac on? do they come on?

Paul Glasson · Paul Glasson's Garage

Bridge your temperature switch on the radiator and see if fan runs. If I recall right, the aircon relay is in series in the same circuit so can prevent fan coming in if faulty. Put aircon on and see if that fan runs.My radiator fan kicks in about 2/3 on the temperature gauge.Also check the fuse in the circuit. Hopefully you have a manual to check the wiring circuit, but there is a wiring diagram in the technical forum. There has been quite a lot discussed on this subject in the forum.Do a topic search, something like cooling fans, and you should find a lot of useful information.

Cebu · 09-01-2003, 10:42 AM

There is a Fan Relay in the system ..(a bit pricey)..if neither fan is working check this relay in the Central fuse/relay box. If this is a recnt failure of both fans it is most likely the relay. The relay is primary for control of the fans after ignition is off

bearone2 · 09-01-2003, 12:25 PM

check the cooling fan and A/C fuses, #3&5 in the smaller fuse block.

ds475 · 09-01-2003, 12:48 PM

thanks for the input, i'm going to go check that stuff right now

ds475 · 09-01-2003, 01:30 PM

my fans NEVER come on, during or after the engine is running, i just tested it again, which relay is the radiator fan relay?

SoCal Driver · SoCal Driver's Garage

Early or later 85?

Check Pelicans technical articals.

http://www.pelicanparts.com/944/944tech_articles.htm

Think www.frwilks.com has a diagram of the early fuse-relay block.

ds475 · 09-01-2003, 04:05 PM

early 85, and i checked the relay by applying some voltage across the inductor part, and i can here the relay flip, so i'm assuming the relay is fine. for now, would it be alright to wire my radiator fans to the battery direct? they can handle that much amperage, correct? and, where can i find the thermo for the fans?

Paul Glasson · Paul Glasson's Garage

The fan will only draw the current it requires unless it is shorting.Test it for a few secs first before fitting a temporary connection. But dont drive around too long like this you know the expensive consequence. Did you bridge the switch to see if that was it?

ds475 · 09-02-2003, 11:38 AM

yea, i bridged the relay, still nothing
where is the thermostat for the radiator fans?

Baza · Baza's Garage

Its in the radiator on the left under neath the top radiator hose.

mike944 · 09-02-2003, 08:41 PM

have you (or a previous owner) ever replaced the fan relays in an attempt to fix the problem?

There's a bit of bad factory documentation out there. If the relays were ever replaced, it's likely that the wrong relays are in there, which causes the fans to not work at all.

Here's how to check:

pull the 1st and 3rd relays http://www.frwilk.com/early944/misc/relay.htm

Grab a flashlight, and count the copper contacts inside the 1st and 3rd sockets. The first socket should have 6 contacts, the correct relay part number is: 944.615.113.01 The 3rd socket should have 4 contacts. the proper relay part number for the 3rd position is 141.951.253B

The factory documentation has these relays switched. The reason i say count the contacts, is that it could have been a mid-model change in the early cars that i don't know about, and it's possible that this documentation is correct for someof the early cars.

Mike

ds475 · 09-02-2003, 08:57 PM

i found out, that the reason i had two radiator fans, was because the guy had added one, and an inline fuse, to protect it, i guess, and the inline fuse holder melted, i guess from the hard night of driving or something, cause the fuse was not making a connection, because the contacts had pulled apart

long story short, i took the fuse out, cuz i didn't have another fuse holder, so i just stuck it together. FIXED!

Paul Glasson · Paul Glasson's Garage

Think twice about bridging fuses.I am not sure if an extra fan was added as the cars have two fans when aircon fitted. If the fuse holder melted there is low resistance in that circuit so the fan could be faulty and drawing too much current or there is a wiring fault. With no fuse you could cook the wires supplying the fan and possibly set your car alight.