Electronic Fan cutoff problems
Thread Starter
Instructor
Joined: Aug 2004
Posts: 102
Likes: 1
From: Montgomery Alabama
Electronic Fan cutoff problems
I installed an Electric Fan last year and I've had two problems with it shutting off. I don't think it's the fan but possibly the relays, I have the two speed fan from with a 175 on low speed and 190 on high speed. I have all the relays mounted in an outdoor plastic electrical box in the engine bay. Both times the fan cutoff it was very hot such as on Friday here in Montgomery Alabama. It was at least 95* outside and the water temp. was staying around 205 to 210 in the dead heat sitting still in traffic, I have a GM crate motor with headers and A/C. Could the relays be getting so hot they shutoff? I have the box mounted on the fender they are not close to the headers but with the new fan setup mounted on the radiator it doesnt move much air around in the back of the engine compartment?
both times after the fan shut off and waiting around a few minutes with the hood up it I tap on the box housing the relays I got it start blowing again. Should I try and move all the relays to the inside of the car? any other suggestions?
both times after the fan shut off and waiting around a few minutes with the hood up it I tap on the box housing the relays I got it start blowing again. Should I try and move all the relays to the inside of the car? any other suggestions?
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
I installed an Electric Fan last year and I've had two problems with it shutting off. I don't think it's the fan but possibly the relays, I have the two speed fan from with a 175 on low speed and 190 on high speed. I have all the relays mounted in an outdoor plastic electrical box in the engine bay. Both times the fan cutoff it was very hot such as on Friday here in Montgomery Alabama. It was at least 95* outside and the water temp. was staying around 205 to 210 in the dead heat sitting still in traffic, I have a GM crate motor with headers and A/C. Could the relays be getting so hot they shutoff? I have the box mounted on the fender they are not close to the headers but with the new fan setup mounted on the radiator it doesnt move much air around in the back of the engine compartment?
both times after the fan shut off and waiting around a few minutes with the hood up it I tap on the box housing the relays I got it start blowing again. Should I try and move all the relays to the inside of the car? any other suggestions?
both times after the fan shut off and waiting around a few minutes with the hood up it I tap on the box housing the relays I got it start blowing again. Should I try and move all the relays to the inside of the car? any other suggestions?
If moving the relays a good place is in front of the core support and the closer the better for dc voltage drop. Really no need to put them in an enclosure.
Here are many samples
http://www.texasindustrialelectric.com/relays.asp
Racer
Joined: Jul 2007
Posts: 397
Likes: 0
From: Warren IL
How much current does your fan draw on startup and once running? What are your relays rated for? It sounds like you are using under sized relays but, we need details to say that for sure.
I question the need for the big bulky solenoid looking "continuous duty" relays. Probably overkill. Just make sure that your relay is good quality and rated for the correct amp requirements.
I question the need for the big bulky solenoid looking "continuous duty" relays. Probably overkill. Just make sure that your relay is good quality and rated for the correct amp requirements.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If you scroll down the page I linked, you will find that the 40 and 50 amp continuous duty ones are of the Bosch style and no larger than the common ones everyone is used to known as "mini relay".
Higher rated relays normally have more robust latching coils beside contacts, but the op's problem could simply be heat.
Higher rated relays normally have more robust latching coils beside contacts, but the op's problem could simply be heat.
