danialz

Hi guys

I've searched.

I have replaced 2 relays in 30 days. I've done the solder fix. But still problem occurs. Make things worst there is burn marks on the fuse box and the relay it self. My mechanic reckons the fuel pump is about to give way. It's demanding more current as it's inefficient. Doesn't make much sense to me. At the same time, the fuel filter is probably factory fitted. Keep in mind I just got the car 3-4 months now.

Any ideas why the fuse box and relay will burn out like this?

BobbyT

That much heat would make me wonder if a previous owner had installed a higher amp fuse or done some creative wiring in the fuel pump circuit. It should blow the fuse before the circuit gets that hot. I would check fuse #26 to make sure it is 15 amp.

danialz

Picture of the fried relay. This has happened to 3 relays all from different manufacturers

Vorsicht

Given this has happened on three different relays one would think it is not the relay but the wiring.

As above check to make sure the #26 fuse is 15 amps and looks normal. Has there been any work on the car lately? Any fuel pump or O2 sensor work? Has the fuel pump been getting louder lately?

This is certainly not normal behavior. If you are not DIY inclined have an Indy shop look at it. They should be able to test the electrics at the fuel pump to determine if that is the culprit.

Paul902

I agree, check the fuse for proper rating. Better to go through fuses than relays, and socket boards! Your tech could be right on. I would think it is in order to pull the fuel pump and bench test it for flow rate, and current consumption. I would also check the circuit diagram to see if anything else is operated through this relay. If all the above checks out, check and inspect the wirring for short circuits.

danialz

Fuse is 15amp. And yes I replaced the O2 sensors. My first DIY to be honest. Did I screw something up in the process?

Fuel pump is not loud

Vorsicht

The fuel pump and O2 sensor are on the same electrical circuit. Using a flash light look at the wiring from the O2 sensor(s) all the way up to where it goes thru the rubber grommet. Then look in the engine compartment and check the wiring all the way to the connector. You are checking to see if the wire is crimped or burned (from the exhaust, for example). Also, disconnect the connector and look to see all is well (i.e., no burn marks, pins aligned). Let us know what you find.

NP993

Before you do serious damage, if you haven't already, you might want to stop putting relays in the car that burn up. Jeez.

Stop driving the car. Verify you have the correct amperage fuse. Inspect the wiring. Test the fuel pump.

danialz

[QUOTE=NP993;11563403]Before you do serious damage, if you haven't already, you might want to stop putting relays in the car that burn up. Jeez.

Stop driving the car. Verify you have the correct amperage fuse. Inspect the wiring. Test the fuel pump.[/QUOTE


Fuse #26 according to the label is 25A and it is correct. The car is with the Indy now. Checked the O2 sensors cables and connectors didn't find abnormalities. Gonna fit new fuel filter and dismantle the fuse box for further inspection.

Texas993

Dan,

I had the same issue and resolved it. Same burn marks, etc. And no one knew the solution (with lots of intelligent diagnosis as you see above.) Exact same issue, but my relays would blow after a few months or years.

I replaced my fuse panel. I pulled the old one apart and it was really nasty inside. It was so corroded and burned up, I couldn't believe that the electrical system worked at all.

Buy a used fuse panel from OK Foreign (approx $200) and carefully change it out. Disconnect the battery. Take pictures of the fuses, relays on top, pull them, remove the fuse board with the few screws. The wires disconnect very easily from the rear side of the fuse panel and they are all labeled with letters so you don't have to do that yourself.

You can, for precaution, replace the fuel pump. It is very cheap on your car (<$200) and very simple to do. But that was not my issue.

My theory after owning my car for more than 6 years is that a bad DME blew with flames of glory. Problem with a bad DME design, not any wiring. But that bad DME fried the fuse box. Subsequent DMEs are blowing due to poor connections, arcing, and inconsistent power within the fuse panel.

Good luck and feel free to email me at my username at gmail.com. (I don't check in here very often)