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Discussion Starter #1
My 1996 Roadmaster got hotter than normal in traffic last Friday. As soon as the car was moving and not sitting the temp returned to normal. I looked under the hood and neither of the electric fans were running. I can't believe both would die at the same time. Is this a fuse or relay? Where do I check for either? This car is not a tow package car and does not have a mechanical fan.
 

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pull the primary fan relay from the under hood fuse block.....are the prongs on the relay burnt?....is the plastic around the female terminals where it plugs in melted?

if so...you need the "move the fan relay" mod. GM issued a TSB back in the 90's about this

Gary at Innovative Wiring LLC also made a kit to fix the problem
 

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First, with key on and engine off, pull the pigtail to the CTS on the waterpump. One fan should come on and a couple of seconds later the other one. If one does not come on, try switching the relays. If it comes on after the switch, replace the relay with a new one. If it doesn't make any difference, the relays are OK and it is probably time for a new fan motor.
The motors are fairly cheap and easy to replace. Even if the relay turns out to be the problem., the most likely reason the relay went bad is that the motor is failing. The fan may appear to be running and yet be failing and not pulling enough air.
FYI, it is a rare occasion for both fans to be on. The primary fan(passenger side) should be on when the A/C is on. Otherwise, it only comes on when the temp exceeds the ridiculous factory turn on temps. The secondary fan only comes on when the temp gets even higher.
The most likely cause of your problem is a failing or failed primary fan motor. Good luck.
 

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Discussion Starter #4
I checked the fuses and relays and they all looked fine. The fuse box showed no sign of melting or overheating. I started the car and then pulled the temp lead from the water pump, still nothing. I will check for the ground tonight and then try to jump the fans. This car has 120,000 miles but it still seems odd that both fans would die at the same time.
 

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unlikely "both" fan motors puked at same time...

so if the relays & fuses check out and no sign of heat/burnt/melted terminals on relays or where the plug in....get out the DVM and back probe from fan harness back for continuity and 12vdc. will have to start car and turn on AC so primary fan would be "triggered" to be on

you can also run 12vdc to motors with temp wire from battery just to confirm they "work"
 

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Also check the 4 pin fan connector at the passenger frame rail for signs of being melted. I just noticed that mine has a very small section on one of the wires that is melted. My primary fan is not currently working and I just checked tonight the relays and wiring (both good) fan motor died on me (this was a four seasons #35656 replacement from 8/14). Looks like i'll be making another cooling system purchase tomorrow.
 

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Discussion Starter #7
Well.... I turned on the air cond. last night and the primary fan came on just like it should. When the car ran hotter than it usually does and the temp came down once it was moving I guessed the fans were the problem.
 

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My 1996 Roadmaster got hotter than normal in traffic last Friday. As soon as the car was moving and not sitting the temp returned to normal. I looked under the hood and neither of the electric fans were running. I can't believe both would die at the same time.
The other explanation is that the fans have not been reprogrammed to turn on sooner. GM set the fan-on thresholds VERY high, well hotter than necessary.
Is this a fuse or relay? Where do I check for either? This car is not a tow package car and does not have a mechanical fan.
Assuming it is an electrical issue, the other possibilities are the wiring, and/or the connections in the fusebox.

TSB 53-62-04 addresses upgrading the wiring and relocating the fan motor relays OUTside the fusebox so the connections never melt.
However, GM only applied TSB 53-62-04 to non-9C1 vehicles.
Correct GM's penny-pinching by going to
Innovative Wiring and purchasing the TSB harness [scroll down a bit].
 
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