Fuel pump relays going bad

[Barry Eller]

I am having problems keeping fuel pump relays in my OMC 502 King Cobra from going out. I have traced the power each time the relays quit, no power to fuel pump. I replaced the pump thinking it was drawing too much current, but no difference. The engine will crank and run fine up to 3000 RPMS, then starts cutting out, dying and not restarting until a new relay is installed.
Does this sound like the Coil/module causing the problem or possibly the alternator causing this?

[mrfixxall]

I am having problems keeping fuel pump relays in my OMC 502 King Cobra from going out. I have traced the power each time the relays quit, no power to fuel pump. I replaced the pump thinking it was drawing too much current, but no difference. The engine will crank and run fine up to 3000 RPMS, then starts cutting out, dying and not restarting until a new relay is installed.
Does this sound like the Coil/module causing the problem or possibly the alternator causing this?

whan an alternator is going bad it throws a/c voltage which will distroy more the the relay...ck your volts if it reade 13.8 > 14.2 then its ok...a bad ground to the relay could cause the relay to go bad..Also check the relay sockit,make the terminals are tight on the relay..remember seeing a battery terminal that was loose? the ends melt which transfers heat ,you may have the same thing going on in the plug...

[MOP]

Barry 502 with a King Ah what a sweet package!

Usualy what kills those relays is an over voltage condition, check the output from the alternator. You can clip into the #86 or #15 lead at the relay for + and any decent ground, if you are exceding 15v that is a good possibilty. Do you have the Bosch or another type relay? It is a simple 4 pole relay and can be swapped to a heavier grade, many in the auto industry will take up to 18v before the crap out.

Phil

[Barry Eller]

Thanks for the information. I'll try to find a heavier relay tomorrow. I will have to get it started again to test for voltage as the 3 relays I have now are shot. The plastic housing the relay plugs into is melted as a result of heat. I have removed the wires and butt connectors from the housing and cleaned them up. The housing has two sides to it, so I can reinstall the connectors to the other side. I found a OMC module/coil on ebay for the same year King Cobra 502, it is coming. As soon as I get the beast started again, I'll check voltage. I think a new alternator is in order anyway for good measure and dependability.

[need for speed]

had the same issue on my 454 omc king... check the fuel pump wires to! drove me nuts....the harness has some diodes in it and mine where shot.. new harness she was good to go...

[Barry Eller]

had the same issue on my 454 omc king... check the fuel pump wires to! drove me nuts....the harness has some diodes in it and mine where shot.. new harness she was good to go...


Pulled the Alternator and took it to Arco and had it tested. Alternator is perfect. I guess the wiring harness is the next step.

Need for speed, did you replace just the harness that goes to the relay and fuel pump? Or did you have to buy everything? Where are the diodes located in the harness?

Thanks

Barry

[need for speed]

follow leads from fuel pump relay pull back that black tape and u will see 2 bumps in the wires those r the diodes that did me in...

i did n't get a new harness the first time, (i could n't find the right one) so i got a few new diods and put those in ,, and the clip that goes on to the fuel pump did n;t look good so i got a new clip to make a good conection at the fuel pump..:crossfing

for the diods... i found the same ones at some store on the net just match the number u see on them

[MOP]

Radio Shack to the rescue!

[Barry Eller]

Radio Shack to the rescue!


If parts from Radio Shack fix my boat, will my boat be considered a "Radio Controlled" boat?:yippie: