Melted Fuel Pump Relay

[Jlarsen79]

Well...I think I figured out my no start issue. Pulled the fuel pump relay and it’s melted in one corner. My concern is that there appears to be some heat damage in the box as well, where the relay was plugged in. Think I need to replace the whole box? Also, what could’ve caused this? 

[electricjohn]

The holding coil in the relay could be shorted or the relay's contact for the fuel pump could be overloaded by the fuel pump's current draw. A shorted coil could harm your ECM's driver for that circuit.  When you say box, are you referring to the relay's socket?

[blk93jeepzj]

Went thru this about a month ago.  I burned up a couple Relays last year and then one this year.  From some great advice here thanks to TMC I took a look at the socket and discovered that it had melted a bit as well and that is what was probably causing the relays to fail.  Since the socket had melted there was a good chance that the metal was not holding as well and with some vibration it was causing a bad connection and heat.  

I went ahead an replaced the socket and relay this time.  So far so good.  

[electricjohn]

I think 93jeep hit the nail on the head.  Loose fitting sockets will cause arcing and heat.

[jeffdiddy]

On 7/7/2020 at 4:46 PM, blk93jeepzj said:

Went thru this about a month ago.  I burned up a couple Relays last year and then one this year.  From some great advice here thanks to TMC I took a look at the socket and discovered that it had melted a bit as well and that is what was probably causing the relays to fail.  Since the socket had melted there was a good chance that the metal was not holding as well and with some vibration it was causing a bad connection and heat.  

I went ahead an replaced the socket and relay this time.  So far so good.  

Can you provide a parts link and instructions on how you replaced?  I’m having the same issue on 2019 A24 with PCM Monsoon 450. Thanks!

[jeffdiddy]

19 minutes ago, jeffdiddy said:

Can you provide a parts link and instructions on how you replaced?  I’m having the same issue on 2019 A24 with PCM Monsoon 450. Thanks!

@blk93jeepzj 

[blk93jeepzj]

On 7/3/2022 at 11:07 PM, jeffdiddy said:

@blk93jeepzj 

 

On 7/3/2022 at 10:47 PM, jeffdiddy said:

Can you provide a parts link and instructions on how you replaced?  I’m having the same issue on 2019 A24 with PCM Monsoon 450. Thanks!

Sorry. I’m on vacation and haven’t really been checking emails. Let me see if I can track some info down for you. 

[blk93jeepzj]

@jeffdiddy
This looks to be the correct relay that I used.  Should be able to cross reference too.

https://www.oreillyauto.com/detail/c/masterpro-ignition/masterpro-ignition-30-amp-5-terminal-multi-purpose-relay/mpi0/2dr1059?q=Relay+harness&pos=10

Here is the relay through skidim too.

https://skidim.com/relay-12v-gm-fuel-pump-system.html

 

This should be similar to the harness that you need to replace. Any of the auto parts stores should have one on the shelf. I just happened to be at a “Bumper to Bumper” picking up other things and they had the one I needed along with the relay. 
https://www.oreillyauto.com/detail/c/murray-climate-control/murray-climate-control-5-terminal-harness-connector/mry0/37232?q=Relay+harness&pos=31

As for replacing, I cut and connected 1 wire at a time for all 5 wires to make sure that they were connected to the correct original wire. Used heat shrink butt connectors. 

Edited July 6, 2022 by blk93jeepzj
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