Starter solenoid questions

[evo45]

Can I use a starter solenoid as a relay for full time use? I am having a problem with my relay for my FASS pump getting really hot and I am thinking about using a starter solenoid as a relay for the pump. I have rewired everything a couple times thinking that there was a proble with my home made wiring harnes but the relay is still getting hot. I think the problem is that I am running on w85 and it is harder for the pump to move so it is drawing more amps and causing the heat. Let me know if you guys have any other ideas for a relay.

Thanks

Vic

 

[Tom S]

Those starter relays are generally not made for continous duty . There are relays styled like that that are rated properly. You could also google 12v contactor for some ideas on high powered relays but that might be more then what you need for a fuel pump.

 

[evo45]

Now that I have used google I found this place, http://www.texasindustrialelectric.com/relays.asp seems to have everything that I could use. I guess I should have looked this stuff up before I asked. From what that site is sayin, most of the Ford starter solenoids arent made for continous duty like you said. They do have some that are but I have found 70 amp small style bosch relays. I am guessing they shouldnt get as hot if they are capable of handling 70 amp.

 

[QtrHorse]

I would check to make sure you have a good ground.

What size of wire are you using for the power wire? If you are using 14ga, that may also be your problem. You want the least amount of resistance going to a fuel pump. I would recommend 10ga wire.

Below is a picture of the Bosch 75A relay. They are quite large but not as large as a starter type relay. I have used these large relays in the past to supply power to a small add on fuse block. You do need a continuous duty relay.

How exactly did you wire/ make your home made wire harness? Did you run power directly from the battery to the relay or use a power wire from a harness or fuse panel?

If you want some good reading on 12V electrical, look at the bcae1.com website. It has a lot of very good 12V information on it. It has subforums for things such as relays only and how to wire them/ use them to turn things on or off.

 

[evo45]

I have run a 10 guage ground directly to the battery from the pump. I have run 12 guage wire from the battery with a 30 amp fuse inline to the relay and 12 guage wire running back to the fuel pump. I have the stock fuel pump wiring to turn the relay on.

 

[evo45]

Qtrhorse, where did you get that relay from? I am hoping I can pick one of those up at a local autoparts store. That may solve my problem. While I am replacing that I think I am going to put 10 guage power wire in too.
Thanks

 

[QtrHorse]

I bought them off Ebay. I check for them from time to time to see if I can get a good deal. They normally sell for around $50. There is another brand on Ebay called Tyco or something like that and it sells for around $25.

 

[bigbadford01]

You have a bigger problem going on. What type of relay are you using? Need to use 30a bosch or tyco same company. You should not be pulling enough amps to heat that relay up. no need to run ground all the way to battery. I'd suggest moving to 10g on the power side. When the pump is running are the terminals @ batt. and or relay physically hot? Bad connections = heat due to high continuity.. FWIW. I have a 20a fuse in my FASS pump relay. no issues