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#1078 of 1159 Re: Fuse Panel - 2000 Buick Century [2000buickrehab]
Sep 29, 2009 (10:44 am)
I don't have schematics for your vehicle, but generally yes I would look for a relay. The fan motors draw high current, so there is generally a relay (or two), but I have had a Chrysler that performed the same function with a transistor heatsinked to the vehicle frame.
You can check out the fan motors themselves, by applying 12volts directly to the motor to verify that the fan motor itself is good. Before doing that, I always (with all power off), spin the fan blade manually to make sure it's not bound up. Check also the fuse to the fans. Assuming the fans work and the fuse is okay, then you know the problem is in the control circuitry as opposed to the fan motor.
The control circuitry differs obviously by mfg, year, make, model. I've seen a couple different logic being used on fans:
- two fans, one is turned on by high engine radiator temperature, the 2nd fan turned on when the a/c is turned on. Computer logic turns on a relay, which turns on a fan.
- two fans, both turned on low speed based on high engine radiator temperature (they do this via a relay, where the fans are wired in series, hence they run at half speed), and when the a/c is turned on the relay switches and the fans are wired in parrallel, hence both running at full speed.
- one fan, controlled by logic and relay,
I'm sure there are other valid combinations of circuit control.
You would probably have a pretty big fuse (like 20/30/40 amps) for the fans, find that in your owners manual and make sure that isn't blown. Then check to see if the fans will work with direct power given to them. Then at that point, look for the fan relay(s).
#1079 of 1159 Re: Fuse Panel - Buick Century 2 [2000buickrehab]
Sep 29, 2009 (10:57 am)
You posted a bunch of other problems here, while I was trying to answer the radiator fan question. Seems like you've got larger electrical issues than the fans.
Again, I don't have any electrical schematics for your vehicle, which you may want to locate/buy/subscribe to. I'll give you some generic things that I would look for:
- check first that you have a good battery, should be putting out 13-14 volts, have good solid, no corrosion connections to the wiring.
- Many vehicles will have a 'fusible link', or big chunk of metal that acts like a fuse, generally rated around 100 - 150 Amps.Think of this as the fuse to the main set of fuses.
- There are some fused circuits, which are supplied power all of the time from the battery. Thinks like security system, lights, power door lock opener, etc. There could also be relays in this circuitry, to handle higher current levels.
- There are some other fused circuits, which are only supplied power when the key is in the ignition and turned on. There could also be relays in this circuitry, to handle higher current levels (for instance, the key in the ignition turns on the relay, the higher current relay points provide the power to those fused circuits). Things like radios, heaters, a/c, defroster windows, etc
When you have a number of items that are showing symptoms of electrical failure, start with your basic main battery power feeds, and verify that they are working.
#1080 of 1159 Re: Fuse Panel - 2000 Buick Century [kiawah]
Sep 29, 2009 (10:58 am)
Pulled and checked all 3 fan relays from the fuse panel in the engine, all 3 "clicked" when powered, even bought a brand new one to cycle through, still nothing. I am going to go back and start at the fans and follow back through the connectors and harness until I start getting some current somewhere. Thank you for the assistance.
#1081 of 1159 Re: Fuse Panel - 2000 Buick Century [2000buickrehab]
Sep 29, 2009 (11:01 am)
If you have 3 fan relays, then I would expect the logic to be where one of those relays connects the fans to be in series for low speed, and then in parallel (or direct power connect) for high speed.
#1082 of 1159 Re: Fuse Panel - Buick Century 2 [kiawah]
Sep 29, 2009 (11:04 am)
KIAWAH, thanks for the recommendation. I have the 3 volume service manual for the 2000 Regal/Century, straight from GM, however, I have issues with following any schematics in there becasue the first few exploded engine diagrams were mislabeled and some components completely missed. The Haynes manual has too little information to be of much assistance with this issue.
#1083 of 1159 Re: Fuse Panel - Buick Century 2 [kiawah]
Sep 29, 2009 (11:07 am)
New battery went in 2 days ago, was a little surprised to find the prior one to have less than 10 volts with a dead cell, it was less than 2 years old, stuff happens.
#1084 of 1159 Re: Fuse Panel - Buick Century 2 [2000buickrehab]
Sep 29, 2009 (11:14 am)
I've always bought the factory service manuals as well for my GM vehicles. I haven't seen the problem you reference with mis-labeling, so not sure what to expect with that.
#1085 of 1159 96 Range Rover 4.0 Electrial problems
Oct 29, 2009 (12:41 pm)
I have a 96 Range Rover SE 4.0 ac,at,4x4 pb,pw, etc. I was haveing trouble with it being underpowered and running rough, I did an ohm check on the plug wires they were ok then did a spark test from the coils, the two of the coils on the drivers side both were bad no spark at all the after futher inspection I could see that they were heat warped. I replaced with a complete coil pack 4 coils fixed a couple Exhaust leaks put it back togeather did a test drive it died, a complete loss of power I replaced the20amp main electrial fuse went back and checked the coils again and the same ones in the new coil pack were melted down same as before and the vehical still ran rough as before ? can anyone give me some insight ?
#1086 of 1159 Help me/girl mechanic
Aug 31, 2010 (2:55 pm)
I have a 1980 Toyota Corona that has been dying on me while driving. I have replaced the ignition coil, plugs and wires, alternater, checked distributor cap and the pick-up coil. It seems to die when it gets hot or I run the A/C and will not start again for usually 15 minute, sometines longer. When it does this there is no spark coming from anything.Does anyone have any suggestions about what this could be?
#1087 of 1159 Re: Help me/girl mechanic [sosteen]
Aug 31, 2010 (3:13 pm)
I don't have a set of electrical schematics for that vehicle, and if it were me that's where I'd start.
You'll have to meter out some circuits, when you have a failing situation. Verify that the keyswitch is good, any relay's that are in the circuit, eliminate any aftermarket security systems, and verify that you are getting power to the distributor, etc.
Don't throw any more parts at it, until you figure out where the problem really is.