Combines R cab blower

I've not done this myself, but I do know how a relay works and how to wire one in. A relay has input voltage (voltage to power blower),control voltage (voltage from console switch),and ground lugs (to the console and to the blower). You buy them for whatever application you need. I think in the gleaner the voltage is all the same. 12v console switch, 12v blower. So now all you need is to get the amperages correct. Relays come in all different amperages. The input voltage (to power the blower) should be somewhat higher than what your console switch is currently rated at. You control voltage terminal should match your console switch amperage. To find out console switch amperage find the fuse between the console swwitch and it's power source and match that. To find out the blower motor amperage match the fuse between the console switch and the blower. Relays are readily available at auto parts stores, and can be custom ordered anyway you want them through your local Radio Shack. I hope that made sense. OKFarmer

if you are 'burning' switches, you have too high an amp draw either at the blower or comp clutch. We have installed a relay for high speed, this takes the compressor clutch out of the curcuit of the switch_clutch_blower. We have had customers by mistake, wire the comp clutch to the relay - hey it works just as well.

Also make sure that the relay is 100% duty cycle. That is to say that it can remain activated all day without over heating the coils which magnetize and engage the load circuit. For example a Ford starter relay will switch a large amp load. However even if there is no load in the switched circuit it will over heat and fail if engaged for too long. A short duty cycle.

The "Bosch" Relays for the horns on vechiles are all we use. They are a 30 amp relay. Over many years they have proved to be the most reliable relays we have used as well as cheap. Rolf installed them on the frame under the cab near the blowers. One relay for each of the 3 [ R62 ] blower speeds. The cab switch and standard fan leads to the fan are used to activate the appropiate relay for the fan speed required. A heavy lead from the main power lead and relay under the console is taken to the relays. We also use a this relay mounted in the A _C compressor circuit at the back with a short heavy lead from the starter _ battery connections. The standard compressor circuits are used to activate the A_ C compressor. Using the relays has given excellent reliability over the last 5 or 6 years with no switch problems and good performance from fans and etc as any switch and loom resistance problems are almost non existent.

Good point guys on the relay needed for each speed. I did not include that in my original post. Bosch has relay "clusters" also available that make this little project a lot cleaner. No trying to find places to mount relays securely. OKFarmer

G'Day Guys I have got pictures of our fan relays setup if you want, send me and email by next Tuesday and I will send them on. Rolf

Wrong Email Try rshedt (at) bordernet.com.au