Wiring?

[87boostedbuick]

Ok so as some of you know iv been looking to doing a dual fan set up but before i go to much further with it I am having an issue with my stock fan wiring I'd like to get sorted out and I'm kind of at a loss I have the stock fan wired to a override switch so I can turn it on when ever I want but it still runs automatically but here's the issue it's been not working some times it won't kick on by its self or with my switch then a little later some times 5 min later some times the next day it starts working again with no issues then a few days later it stops again any ideas?

 

[RmvBfrFlght]

Sounds like the relay(s) is going bad. They are located on the drivers side under the hood. There will be 2 or 3 of them, the 3rd being the delay relay which much of the time is removed.

If this is low speed only (high works OK), it is also possible that the big resistor on the fan is going bad.

RemoveBeforeFlight

 

[87boostedbuick]

The delay relay is going bad? How do you remove it and keep the fan still working is there a way to remove it and just loose the delay and keep the rest working like normal?

 

[GNVenom]

Look at:
http://www.installationinstructions.com/FYI/delay-relay.pdf

 

[RmvBfrFlght]

The delay relay is going bad? How do you remove it and keep the fan still working is there a way to remove it and just loose the delay and keep the rest working like normal?

Yes, with the delay relay unplugged the fans still operate as normal. Only thing lost is the turn off delay on a hot engine. The reason the delay relay gets removed is that they go bad, turn on the fan late at night, and the battery is dead before you get up in the morning.

The remaining two relays, one is for low speed, the other for high speed.

RemoveBeforeFlight

 

[Squid4life]

The reason the delay relay gets removed is that they go bad, turn on the fan late at night, and the battery is dead before you get up in the morning.

Odd question, but is this circuit fused in the stock fuse panel? Not near the car or even a computer right now, but this conversation has me wondering something. Once upon a time had a batt drain overnight issue, and was curious if this could have been it...

 

[RmvBfrFlght]

Odd question, but is this circuit fused in the stock fuse panel? Not near the car or even a computer right now, but this conversation has me wondering something. Once upon a time had a batt drain overnight issue, and was curious if this could have been it...

The power feeds to the delay relay are convoluted. The +12 V power to the relay contacts which go on to the fan are from a fusible link off the starter solenoid. That is a heavy gauge red wire.

The delay relay coil +12 V feed is from the 10A ECM/SOL fuse.

Here is the strange part, there is another feed to the delay relay via the 30A Pwr Brk fuse (PowerMaster fuse). This feed also goes to the power master. Why the delay relay requires it, I don't know.

edit: the Pwr Brk feed to the delay relay must be so that the relay will activate with the key-off. The ECM/SOL circuit is dead at key-off. So why use that feed at all?

edit 2:

> So why use that feed at all?

To answer my own question, so that the delay relay knows that the ignition is off. Which is when the delay relay would be active.

RemoveBeforeFlight

 

[87boostedbuick]

Ahh maybe that's why my fan is acting up when I swaped to vac brakes I pulled out the pwr brake fuse

 

[RmvBfrFlght]

Ahh maybe that's why my fan is acting up when I swaped to vac brakes I pulled out the pwr brake fuse

That may be. If the power brake feed wire/connector under the hood won't short on anything can put the fuse back in. Otherwise, could unplug the delay relay.

RemoveBeforeFlight

 

[87boostedbuick]

My fan override switch was working intermittently also and that's wiring to the delay relay so I'm thinking this just might be it but still wondering as to why it would work only sometimes but iv seen stranger things caused by fuses so maybe ill give this a try and hope for the best