installed the re-wire kit as per STM dircetions.... @ the relay:

#30 (blue wire) - feed wire from battery.
#87 (yellow wire) - when cutting stock 12V pump wire, this is to the pump side.
#86 (black wire) - when cutting stock 12V pump wire, this is to the car side.
#85 (white wire) - chassis ground


the relay gets very warm/hot. the relay connector got melted at one point. check that all connections were soldered and clean. made sure good ground. tested the relay, it clicks and 0 resistance when energized. does not blow the inline fuse. the pump is a brand new 450 walbro. kinda stumped, i think im gonna try a new relay. anybody have any input or ever come across this problem?

 

I had the same issue man. I roasted the harness connector 2 times. It even melted the foam on the seat.

I ended up pulling the rewire kit and running it without hardwire. So far so good.

If I do need more power ill be doing what mrfred did on here. Look at his threads.

My only thought is that the pressure is so high at idle that its back flowing at the pump. Just a thought.

 

Any pics of the connectors that were starting to melt?
Is it the relay base you are talking about?

 

relay base yes

 

Is this the kit?

http://www.streettunedmotorsports.co...walbro_450.htm

 

Bought the pump and re-wire kit separatly., didnt even know that kit was available! And yes melted relay connector

 

Any specs on the relay or part number?
I am thinking they are cheap bases and possibly the terminal connectors may be heating up and melting the base. Maybe use a relay base with a higher rating so the terminal connectors so they wont heat up as much.
If you look around you can find higher quality relay bases that won't heat up and melt.

 

Maybe the return is too small. They reccomend their return kit when u buy the rewire 450 kit. Gotta call stm and get this figured out

 

That doesn't have anything to do with the base of the relay melting.
If the relay, fuse, wiring, terminals, and base are adequately sized for the amperage there shouldn't be any problems.
IF it is wired correctly....

 

Not exactly getting what you are saying with terminals #86 and #87.
You should have 4 terminals.
#85 is the ground. Could be ground or negative from the pump circuit
#86 is your switched positive. Positive 12+ from existing pump circuitry
#30 should be your positive from the battery to the relay
#87 should be from the relay to the new pump
when there is 12v on #85 and #86 it will close the contact between #30 and #87.


Not sure if that is what you were saying or not....

 

I cant tell you if you wired them wrong as I don't have their kit, but I have Deustch Works rewire kit and I have no issues. Even if the fuse isn't popping and your driving enough current draw (amps) through the connector, it will melt if its not up to the temp lol. Granted no fires will happen or anything, because if the base does melt at least the relay itself will keep the contacts away from each other. Maybe look into Deustch Works kit?

 

Fixxed it. Changed relays and no more getting hot or melting. Thanks everyone for your input

 

This happened to me too recently only I changed relays and connectors and it happened again.... melts at the power wire. Just put the oem plug back to stock and am using a bulletproof racing billet plug and play double pumper and relay box. Hoping for the best. Deleting the supplied hobbs switch and using ecu ground on low side to trigger second pump via AEM INFINITY

I think the 450 HP’s draw too much current for thr STM setup’s wiring thickness

 

Can also happen due to a crappy in line fuse block or its connection. I had an issue with my car sometimes not starting after shutting it down and it was the fuse block resistance tripping the relay. Couldn't tell anything was wrong, but when I pulled it the bottom was melted.

I'm running the following and is rated at 100amps for the whole block so I run my 4 channel amp, two 450's, and one slot open.

 

I had a relay base melt on me too it was a hella relay but when I ordered a new replacement the design was different than the old one that melted. This was for a fuellab methanol pump but none the less.