High speed fan not working

[MalcolmV8]

I think my high speed fan quit working. 88 ~ 90F here today. Was just out doing a little fun driving and noticed it was 210F. I was back in the parking lot so instead of just shutting it off I let it idle so I could watch and the temp kept climbing. Around 216 ~ 217F I just turned it off. I had popped the hood and fan was definitely running but really hard to tell if it was running high or low, engine noise, wind was blowing pretty good etc.

Mishimoto radiator in the car.

I thought that little coil module on the side of the fan shroud only affected low speed, I've had to replace that once many years ago.

 

[MalcolmV8]

Pulled that little resistor coil off the fan tonight and sure enough it's burnt up. See the black on the one terminal

On the back side of that same one terminal the plastic is melted. Checked it with a meter and no continuity on that one terminal.

I always thought that coil was for the low speed operation of the fan not high. Must be the other way around because my fan works on low speed only. I'll have to pick up another module. Hopefully can pick it up locally and get back on the road asap.

Anyone know what that fan resistor / module is called?

Thanks
Malcolm

 

[raym5_0]

great, another spare part needed in the glovebox:bash:

 

[cobracide]

1r3z-8l603-aa

Engine Cooling Fan Resistor

 

[MalcolmV8]

Couldn't find it locally so ordered it from Tousley. $37 some change plus $10 shipping for that sucker.

 

[04SilverSerpent]

Is there anyway to datalog and tell if the high fan is kicking on?

 

[MalcolmV8]

Is there anyway to datalog and tell if the high fan is kicking on?

Good question, I'll have to check through all the PIDS and see if I can find something for that. Although I may get false readings. The ECU thinks it's turning on the fan and if I understand correctly it sends a signal to the CCRM module which in turn controls the fan. So unless there's feed back through that chain of devices to report an open circuit at the fan the data log would say it should be on but not that it's actually on.

 

[MysticRob]

Subbing for solution to ghosts of troubleshooting future. Nice work on figuring it out.

 

[mustang john]

Same thing happened to mine, i modified it so it acts purely as a jumper now with no resistor in place. I have a Killer chiller so having the fan run on high speed should improve my KC effeciency... Or at least i hope so. If my experiment fails its a $30 part to replace lol.

 

[MalcolmV8]

Same thing happened to mine, i modified it so it acts purely as a jumper now with no resistor in place. I have a Killer chiller so having the fan run on high speed should improve my KC effeciency... Or at least i hope so. If my experiment fails its a $30 part to replace lol.

What was the effect of bypassing the resister with a jumper wire? Did it make the fan turn on high speed when it should have been on low speed?

 

[mustang john]

What was the effect of bypassing the resister with a jumper wire? Did it make the fan turn on high speed when it should have been on low speed?

Thats what it will do, This is the low speed fan resistor that is controlled when you turn the AC on so i wanted it to go to high speed when the AC came on hoping for better Killer Chiller performance. Havent got the car back on the road yet to confirm anything yet.

The low speed resistor failed and high pressure spikes in the AC system from no air flow over the condensor locked my compressor up, thats how i found out it wasnt working... :fm:

 

[MalcolmV8]

I'm confused by how my fan is not switching to high speed with that resistor blown. You'd think that's for low speed only. Unless high speed is a combination of power to both the low and high speed circuits. I'll find out in a couple days when I get the replacement if my high speed starts working again or still an issue.

I can't find a wiring diagram for the fan so not sure how that resistor circuit is used exactly.

 

[mustang john]

It is for low speed only, the resistor is how it achieves low speed

 

[MalcolmV8]

It is for low speed only, the resistor is how it achieves low speed

If that's correct then my high speed is boned or sucks because it can't hardly keep my car cool under 210 and it was only around 88 outside with normal light driving. Either that or my Mishimoto radiator is not working nearly as good as the factory unit did. All my heating problems started once the Mishimoto went in so I always assumed radiator till I found that fan resistor burnt up and figured that might be the issue.

I've had this box laying in the garage for over a year now. Mishimoto fan shroud.

Figured I'd take a look at it. To my surprise it has a fan on it already. Sweet.

Underside

If my fan performance (possibly radiator) performance still sucks after putting in that resistor in I may just pull the stock fan and wire in this unit.

The fan on the Mishimoto shroud is not nearly as strong as the stock unit (I did some quick testing) but with a shroud covering the entire radiator it could possibly out perform the stock setup.

 

[nstag8r]

Same thing happened to mine, i modified it so it acts purely as a jumper now with no resistor in place. I have a Killer chiller so having the fan run on high speed should improve my KC effeciency... Or at least i hope so. If my experiment fails its a $30 part to replace lol.

Any update on how it acts with the resistor jumped. If there are no issues could you send the info on how you jumped the resistor?

Thanks

 

[mustang john]

Works just fine, when the fan kicks on it just runs at high speed. It still swiches it from the low speed circuit to the high speed circuit but with the resistor removed from the low speed circuit it just turn on high all the time.

 

[svtshadow]

Malcolm, from my experience, my current stocker runs cooler than the mishimoto radiator I had. I thought since the MIshi was thicker, it would cool better, but did not for whatever reason.


One question, with that Mishi shroud covering most of the radiator, do you think it's going to affect highway speed temps?

 

[MalcolmV8]

One question, with that Mishi shroud covering most of the radiator, do you think it's going to affect highway speed temps?

From my experience on other cars no. If it does its not enough to notice.

 

[Kryo-Genik]

Works just fine, when the fan kicks on it just runs at high speed. It still swiches it from the low speed circuit to the high speed circuit but with the resistor removed from the low speed circuit it just turn on high all the time.

How did you jumper it exactly? some 10awg wire with two spade connectors in the plug where the resistor goes? Or did you do it some how else? Id love some pics or a good idea on it

 

[mustang john]

How did you jumper it exactly? some 10awg wire with two spade connectors in the plug where the resistor goes? Or did you do it some how else? Id love some pics or a good idea on it

I cut the resistor out and soldered some decent gauge wire across the terminals on the back side. That way the connector still plugs into the resistor housing and the housing clips into the fan shroud like stock, just no resistor.