Time to get my Low Speed fan working

buickrob

Member
OK, I put on Alky and a front mount so it's time to get the fan all working. I did a search and a bunch of tests on it but nothing yet. My fan does come on at 205 but no low speed.

I tested the red "hot" wires on the relay, they are good. I tested the brown wire on the relay and it is good when the key is on. I jumped the red wires to the black/red wire and the fan did not kick on. Did this both with key on and key off. So, then I figured it must be the resistor since we know the fan comes on when it is 205. Bypassed the resistor, battery right to the "hot" where the resistor connects to fan. Nothing.

Any ideas? I'm not against going with the Casper wiring plug and play but I think my system has to work properly for that to work. Any ideas?
 

buickrob

Member
well did some more testing. Measured volts with a jump at the relay and my meter on the harness. 12 volts, no ground issue. Used a better jumper and got the fan to work right off the battery. Sooooo I knew it had to be between the harness and the fan, resistor right;) Took the resistor off and wired the fan to be on high even when the low speed relay kicks on. Jumped at the relay fine. Started it up, got to 165-170 on my guage and blamo the fan went on.

Looks like all is well. I don't really mind having the fan run on high from the get go because I don't drive the car too much and have a front mount. Hopefully my limited mileage will help the fan motor from burning out and the extra speed will make up for the front mount. I'm just glad to have a fan before 205 :biggrin:
 

buickrob

Member
Just took her on a nice ride through country roads. Fan came on high at 160 and cruising at 35-45 I never went above 175. She got to 180 when I sat in traffic for a few minutes. Glad that's over:)
 

VadersV6

Active Member
9 times out of 10, the cause is the 20 year old die electric grease in the relays and relay connectors that turns almost as hard as plastic and destroys all conductivity. My low speed fan barely worked when I got my car and high speed wasnt great either. You can jump it, but what good is the jumper, when the ground through the relay is horrible as well? I got some ronsonol lighter fluid from 7-11, got some brushes, picks and an air gun, and removed the relays from the inner fender, and cleaned every socket out and every pin, (will take almost an hour to clean it right...you really have to dig deep in the connectors with a pick to get the bulk of it out), and I kept pouring in fluid and scrubbing and picking and brushing and blowing and eventually it was super clean...I sprayed a little wd-40 in the connectors to keep moisture out, and lo and behold, the low speed fan worked like crazy. When those connectors have every slot jammed solid with crap and you have points of conductivity about the size that a spark can barely jump through, current draw is going to be super high and will overload the whole system. Itll be drawing a ton of current from the alternator to get the fan to barely spin. The resistance is crazy with all that snot in there, so its amazing the fan spins at all like that.
 

buickrob

Member
My problem was definitely the resistor but you make a good point about the draw. My relay's were all crapped up. The grease didn't harden but was certainly a thick gooey mess.
 

Evans Ward

Love those LC2/ Y56 cars!
tip

When you change the 3 relays on the driver side, you can use alittle black RTV around the edge where the male and female pieces meet to seal and weatherproof them. You can also fab up a mount bracket above them that acts as a shield.
 
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