NuklearFusion

A friend of mine installed a Painless coolant fan relay a couple years ago and as of tonight, it stopped working. I have absolutely no clue on how to properly test this with a multimeter. When I select "DC mA" on the multimeter, touching the sensor (negative on negative, positive on positive) that is sitting in the water pump actually powers on the fans! If I set this to any other setting on the multimeter, nothing happens. I am trying to find out if I have bad wiring to the sensor or if it is a relay causing this. Any comments or advice? Thanks in advance!

vetteoz

iTrader: (13)

Assuming you have a 2 wire sensor ,
if putting a jumper between the 2 terminals in the sensor connector makes the fan run , then the sensor is kaput and you need a new one.


A "bad" relay either is on full time or doesn't work at all.
As yours is switching the fan on and off you can assume it is fine

NuklearFusion

Thanks Vetteoz. The sensor is a two wire sensor. When I use the multimeter on it, I am not bridging the positive and negative with the multimeter terminals, just trying to get a reading off of them. When I do this and the ignition is on, the fans do kick on. Is it the multimeter causing the bridge even though I am not intentionally bridging it?

I thought that this was supposed to be "Painless", lol.

vetteoz

iTrader: (13)

Could reasonablely assume that on a low Mv scale there is enough current passing through the DVM to trigger the relay.

If you wanted " less pain " you could replace the 2 wire switch with this style
http://www.racerpartswholesale.com/p...n_Accessories2

and just run a single wire from the relay to it as done with the stock setup

NuklearFusion

Thanks vette. I'll bypass the switch for now until I get the replacement switch from Painless.

NuklearFusion

I feel like such an idiot. My thermostat got stuck, no wonder why the fans were coming on with the multimeter. Thanks for the replies!