my radiator fan does not work under any conditions, all fuses ok, wondering which relay is it to check conditions, thanks
Here are the cooling system diagnostic
steps...First does the cooling fan kick on (with engine hot)? If not,
check the fuse, if good then check the thermoswitch in the
radiator (it's about an inch and a half in diameter located on the
lower part of the radiator with two wires ) by disconnecting the
wires and touching them together (again, with engine hot...at least
190 degrees) if the fan comes on, you have a bad switch. If not
connect a 10 gauge jumper wire from the battery to the fan itself
(there are three terminals,,, one high, one low and ground). With
power direct from the battery (and a ground wire, if necessary) fan
should run... if not replace the fan assembly... if it does run then
you have a bad cooling fan relay. It will be located above the fuses on the fuse block... Hope this helps...;-)
Posted on Apr 24, 2009
I have a 91 Buick Century limited 3.3L with a 3300 engine. I ran a diagnostic scan of which produced the two-digit codes 12, 26, and 27, and In attempting to look up these codes, I found a website on about.com which lists the OBD I codes for a 1991 buick, yet, there is no 27 code listed. I did find another site that has a listing of GM two-digit codes for 82 and up non-OBD II, which I would assume should apply to me, and it does list 27 as a quad driver module circuit. Can you please explain to me which chart is correct (or why the no. 27 is listed in one and not the other). Also, can you please explain to me why I would have two different codes (26, and 27) that list the same error, and what exactly do these mean.
DTC 26 and 27 refers to a QDM (Quad Driver Module) fault.
The Quad Driver is a "safety valve" for the ECM controlled circuits, the quad driver controls up to 4 circuits.
There are multiple quad drivers in the ECM. The QDM shuts down a shorted circuit to prevent high current flow from damaging the ECM. So the DTC 26 or 27 will isolate the problem to 1 QDM. You will need a repair manual with electrical diagrams and DTC flow charts to determine which of the circuits controlled by that QDM are failing.
Usually DTC 26 refers to the Torque Converter Clutch solenoid and related circuit. Most likely you have a shorted TCC solenoid or the harness connected to it, The solenoid is internal in the transmission accessible from the side cover.
Also, keep in mind the single most cause for any code will be a power or ground problem. Clean all the battery cables, and any and all cables or wires that attach from the engine to the firewall.
Hope this helps; also keep in mind that your
feedback is important and I will appreciate your time and consideration if
you leave some testimonial comment about this answer.
Thank you for using FixYa, have a nice day.
Posted on Dec 21, 2011
the power windows on my 1991 Buick Century stopped working. they are all down and we can't get them to work.
Power Windows usually have an Automatic self resetting Circuit Breaker located neat the Fuse Box instead of a Fuse. This breaker has probably failed which has permanently isolated the power to the window circuit.
Posted on Jul 30, 2010
I noticed about one inch of water on floor board on passenger side after a very heavy rain. I checked and there was no way water could have gotten in. Could it be heater core? And if it is heater core would it hurt to drive it before replacing heater core?
Engine coolant will feel oily and the windshield will fog up and the car will stink. If it is just water it could be coming from the passenger door weatherstrip at top. The ac drain tube , if stopped up will also leak water in the floorboard.
Posted on Jun 17, 2009
electric fan does not work
This can be due to a bad relay or coolant sensor that turns on the fan or a bad fan, a good test to do to see if the relay and the fan work is to start the engine and then turn on the ac, if the ac doesnt work then unplug the coolant temp sensor this will turn on the check engine light but it will reset when you restart engine, if the fan turns on then fan and relay are good and its the sensor, if the fan doesnt run then it may be the relay or fan, a quick test of the fan is to dissconnect plug to fan and run a power and ground wire to fan and if it runs then you have a bad relay,hope this helps,
Posted on Oct 24, 2010
I have 91 Buick Century with 3.3L V6. The fuel pump will not come on. I have replaced the fuel pump, fuel filter, and the fuel pump relay. All the fuses in the glovebox are good. The fuel pump will still not come on. How can I fix it ?
the fuel pumps circuit starts from the engines oil pressure sensor so replace that item next
Posted on Apr 17, 2011
How to replace a starter for a1991 Century Buick V6.
remove the positive battery cable from the post
remove the 3 wires from the starter and the two bolts holding the starter to the block.
reverse the procedure for installation.
Posted on Oct 07, 2009
got trouble codes for 1991 buick century po12 po34 po 45 po 48 wat does that mean and give me the remedial action for that
91 is OBDI not OBDII. The codes are just 12, 34, 45, and 48.
12 - diagnostic mode
34 - MAF/MAP sensor low voltage
45 - Oxygen sensor rich.
48 - not sure on that one
What engine do you have?
Are there any symptoms?
Ill get you some more info once I know what engine.
I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa
Posted on Sep 26, 2011
how to add freon to a 1991 buick century.
Follow low side aluminum pipe to connector remove plastic cover,134 refrigerant Kits come with a quick connect that will ONLY attach to the low side . Follow kit instructions on can and attatch hose then twist top valve stem puncture can exactly as described. back out valve to relaese refrigerant in line .. Rock can top to bottom as it flows into running engine compressor Must be running !
Posted on Jun 08, 2010
I have a 91 Buick century 3.3l that is reading out check engine codes 12,26,27,44. I can't find a chart anywhere that tells me what the codes mean. Can you help me out? Thanks, Joe
I'll try and help with a few of your codes, code 12, will show if the diagnostic term is grounded to access codes, it will show any time that is done and the engine not running, all other codes will show after. The 26, 27 codes have to do with the engine over heating or a coolant sensor. #44 has to do with you Ox sensor, indicates a lean running condition. Pos. due to engine running hot. .
Posted on Oct 08, 2010
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