Radiator Thermo Switch... November 09, 2021, 12:04:24 PM You may have read elsewhere my end of production MK2 has the radiator fan motor from a MK3 and it seems original to the car.The factory radiator's long gone together with the original thermo switch so unfortunately can't check part numbers.The fan motor is 3 pin.Hellas e-catalogue (and others such as Autodoc) are quite clear about what switch should be on the car, however they are 2 pin items.The cars thermo switch connector is 3 pin (all wired, no empty slots) suggesting the 2 pin isn't correct, but then that may be because my fan motor isn't what would be expected on a MK2There seems to be variations if aircon / towbar etc. are fitted but none of that is applicable to me.Yet again the inter-web is full of conflicting info. plus getting specifics about the fan motor has drawn a blank so far.Are 8v PB MK2 fan motors single or twin speed as standard for example, if single might explain the recommended 2 pin switch.Likewise are MK3 fans twin speed hence the socket on my car?
Re: Radiator Thermo Switch... Reply #1 – November 09, 2021, 01:54:04 PM As I understand it most Mk2 are 3 pin, only early ones are 2 pin which is the same as Mk1. I bought a Mk1 radiator surround (same as mk2) for my old 8v K-jet, it came complete with fan but I had to swap it out for the 3 pin one from my 86 car. I think the third pin supplies the power for run-on, so if you park the car and it's really hot, the fan will continue to go even once you've taken the key out. I could however be completely wrong and just adding to the conflicting information available on that there web.
Re: Radiator Thermo Switch... Reply #2 – November 09, 2021, 02:40:23 PM I'll try wiring up the fan to see if it's double speed or not, and I've since had a closer look at the wiring... a run on feature would make sense from the way it's connected up.I went through this with the 205, though the cause that time was a completely non-standard radiator and twin fan set up. which made it a head-ache to find the appropriate thermo switch with suitable cut on / off temps.The 2 pin switches on the whole seem to be marked as kick in 95 degrees / kick off 90 degrees. Only having one range listed suggests they are for single speed fans.The 3 pin switches all seem to have 2 x ranges listed, suggesting this time they are for twin speed fans (or twin fans I suppose too).The ranges for these can vary quite a bit depending on brand, some have the low speed kick off down at 84 degrees which seems quite cold?
Re: Radiator Thermo Switch... Reply #3 – November 09, 2021, 03:33:29 PM Fan motor is definitely a two speed one, of the three pins on it one is low and another high. Third may be feed / negative depending on how it's set up plus run on? 1 Likes
Re: Radiator Thermo Switch... Reply #4 – November 09, 2021, 04:05:08 PM I always understood the later fan was 2 speed that runs on with the ignition off if the car was hot.scs
Topic: Radiator Thermo Switch... (Read 437 times)
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