Coolant fan issues...

[Scott87]

She was running a bit hot for my liking... 200 to 220 stuck in traffic..

Fan wasn't running decided replace both relays and delay relay... Fixed the delay relay, fan wasn't running under drive conditions...

But the fan now runs when hot when keyoff due to new delay relay.. So that at least functions as it should...

Bought gn1 radiator and dual fan,...
Did more research found Mr. Woods vortex buicks section on coolant sensor and ac compressor high pressure switch...

Ordered a new fan sensor switch installed still no fans under running condition...

Fan will run when hot via delay relay but soon as I put the key into start position fans shut off and won't fire backup.

Disconnected ac high pressure switch.. No fans, jumping around high low relays, no go...

So tried settings my extender chip to race mode... No fans..

Pulled high fan relay, put a jumper wire across fans screaming and temp drops 200 ish to 160 in no time...

So delay relay is working as it should, but fans under running condition are no go.


My ecu looks clean just installed logger didn't see any corrosion on any pins or contacts... Looks like I need to chase wires...


So questions are, with access high pressure switch unplugged should the fans still run via signal from ecu?

 

[turbojd]

Make sure you have 12 volts at the "red" wires for the high and low speed relays.

 

[Scott87]

I do have 12v at both high and low. I am able to jump the relays and run the fans from either relay socket.