Rad fans - pre 89/post 89

[jezza16v]

Hi, I have two 8v gti atm, when idling and up to temp on the post 89 one the fan comes on with a vengance and cools the engine down within 60 secs, on the pre 89, the fan seems much weaker and can be on for 4-5 min before the temp comes down enough for it to switch off. Are the fans different on these models or is the fan on the pre 89 model knackered?     Thanks.

[rubjonny]

post 89 one sounds liek either slow speed setting is bust, or its had a single speed fan/sensor retrofitted.  check the number of pins on the post 89, both fan and sensor should have 3 pins (sensor is bottom of rad, passenger side)

if it does have 3 pins, jump the fan direct from battery. it should come on slow and fast

[jezza16v]

Thanks RJ, its a 3 pin sensor on both. I'll have a crack at jumping the fan at the weekend. I better check that the high speed is working on the pre 89 one as well as it does seem to run a bit warmer and I've never seen it run at full blast.

[rubjonny]

generally they'll never run at full blast as the slow speed takes care of it, the full speed shouldnt cut in till 102degrees, slow speed comes in at 95degrees

[jezza16v]

OK, checked fans on both and both have 2 speeds working OK and both coming on low speed from rad switch but the pre 89 one runs slower on speed 1 than the post 89......except when I jump it off the battery it runs much faster on speed 1, I'm guessing there is some resistance in the wiring or the rad switch? (or does it switch through a relay?) Also both squeak like **** on speed 1 so I'm going to have a go at stripping one down and see if I can get some lube in there. Can't be sure if either of the rad switches work on the high speed though. 

[hayescappa]

Hi, I have fitted a kenlowe fan to mine, it only has two wires, could I connect the low speed and high speed together and connect to the fan, or would this cause problems?

[jezza16v]

Well, the fan speed is dictated by the wiring circuits in the OEM fan motor it seems. The rad switch just turns on the low speed first and then if that isn't enough, the high speed. I reckon you would just connect the low speed switch circuit to your kenlowe so it comes on sooner rather than later, it will still come on at max speed, just at the lower tempreature, if you see what I mean?

[hayescappa]

Cheers.  Will try this when its up and running.

[rubjonny]

if it runs faster direct from the battery than it does from oem loom you have a wiring problem. it will be a little slower though as power for fan goes from battery sall the way to fuebox then all the way back to the fan, so a bit o power will be lost. if its really bad tho you can fix by wiring up a relay for it next to the battery. same way you make a headlight wiring loom, if you look at matey-matey there is a diagram for this. might as well do a headlight loom at the same time!