Temp. Question

[Copasetic]

I have dual electric fans I just installed not long ago when I redid my cooling system. I have the main fan on a temp. switch which kicks on at 185* and my second fan I have on a toggle switch. I replaced my t-stat with a 180* unit. I noticed last night driving down the road that every now and then my headlights and dash lights would get slightly dim (not too much to cause alarm) and then would get bright again.

When I went to go park I sat there with it running for a minute and paid attention to what it was doing and my lights dimming was from when the fan would turn on. Would I benefit from going up to a 190* t-stat? Or would it be better to change the temp. switch that the fan is hooked up to? I'm thinking the t-stat needs to be higher than what it is so the fan would continuously run after the engine reached operating temp. Any suggestions? Thanks!

 

[mnstrburbon]

you need a higher amp altenator check all the graounds on motor to chassie and battery so on it is normal to see a little diming if you hold the gas a little to bring up rpm and increase charging you should not notice it at all.

 

[4X4HIGH]

Are the fans wired through a relay? If not it is very common to see what you experienced. Also electric fans draw alot of current so hopefully you have the correct size fuse or circuit breaker. Typically 20-30 amps.

 

[reddog64]

2x on the relay...
also get a bigger wire from the alternator to the battery...\
Just come straight off the alt directly to the positive battery terminal. your fan is drawing a substantial ammoun of the power the small wire can contain coming off the back of the alternator...

The new wire will run ya a few bucks...
Alternator will be over 100...

Try the new, bigger wire first...

 

[Copasetic]

Thanks for the help guys! I do have my fans on a relay and they are powered directly off of the battery post from my aux battery (dual battery setup). I'm also about to install a 200 amp alt. with a larger wire coming from the alt. going to the isolator. I just didn't know if the t-stat may be too low for it or not because the fan kept kicking on and off.

 

[supernaut]

Here is a link to a thread I started awhile ago regarding thermostat temp choices. As I understand you want to run a stock temp thermostat for a variety of reasons.

I have dual electric fans as well. I think the best system is to have both fans operated automatically by the thermal switch and have both fans wired to a manual switch. That way your system cools most efficiently (both fans doing the work instead of one) and is redundant (auto and manual switching for both fans).

 

[Copasetic]

Here is a link to a thread I started awhile ago regarding thermostat temp choices. As I understand you want to run a stock temp thermostat for a variety of reasons.

I have dual electric fans as well. I think the best system is to have both fans operated automatically by the thermal switch and have both fans wired to a manual switch. That way your system cools most efficiently (both fans doing the work instead of one) and is redundant (auto and manual switching for both fans).

Thanks! I think I'm going to try and swap a 195* in this weekend and see how it does. I don't know if it was just me trying to pay too close attention to it but it does seem that since I put in the 180* t-stat that I haven't been getting as good MPG as before.

 

[augusta-k5]

You still get mpg? With those tires and gears you should be getting gpm!