Problems with main fuel pump relay on 225 Opti 2003

SST1 · May 1, 2011

Hi,

we have problems the main relay whcht switches the fuel pump of our Optimax 225 (BJ, 2003, 108h) (trimrelais are identical)

within the last 5 hours two of the relays blown ...

each time the line (red circle) is concerned ... the plastic from the counterpart is fused to the plug ... (forgot to take photo)

the fuel pump is protected by 20A, the fuse is NOT blown...

Who has an idea what's wrong here ...

Faztbullet · May 1, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

Whats your charging system voltage?

jeffersondodson561 · May 1, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

Did you ever happen to hook you battery cables up backwards? Their is a fuseable link (follow from the altenator lead) you will see it covered in a clear insulated material. Does it look black/burnt?

SST1 · May 2, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

smart craft shows me:
engine is not running: 12.5-12.6 V
engine is running...lower rpm ~13.6 V higher rpm ~14.xx V

the cable comming from the alternator

,
I have to take a look this evening...

the plastic around cabel shoes of the counter piece (plug) is like cement...

jeffersondodson561 · May 2, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

What color wires go to this relay? Check all connections on the starter relay and all grounds. If you have an ammeter take out the fuse of that circuit and hook up in series to measure. It could be your fuel pumps drawing too much but not enough to blow the fuse.

SST1 · May 2, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

the wire with the problems is red...I will shoot a pic from the counter piece (connector) tonight

the 2 relays which are (one after another) broken both clicks (if the key switched on)...but no current flows through

I bought the 3rd (new) relay now...fuel pump is working...problems are gone...but for how long???

SST1 · May 2, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

jeffersondodson561 said:
Check all connections on the starter relay and all grounds. If you have an ammeter take out the fuse of that circuit and hook up in series to measure. It could be your fuel pumps drawing too much but not enough to blow the fuse.

ok, we will measure the A of the fuel pump...how much amp is usually..?

the fuse has 20 and the relay is 30 A...?
the fuse had to come befor the relay...or? this what we dont understand

also the opti dont miss power...
ok its a only small hull -> 17 ft fletcher

jeffersondodson561 · May 2, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

High pressure=5-9 amperes
Low pressure=1-2 amperes

You could take all fuses out except for the fuel pump fuse, and measure here I think and just disconnect each pump to test.

SST1 · May 3, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

thank you jefferson, for the informations...

I was wrong...its not the red wire but the red wire with the white stripe :redface:

ok, what I did yesterday:

-> I checked all the connections + and - and battery...
-> I checked the wire comming from the alternator...their is a fuse (100A) covered in the clear insulatet material...its not black/burned
-> I changed the cable lug on the plug (pic next post)

Meassuring the A will be the next job...

should I do it on the water, or it is possible to meassure it on the flusher...

SST1 · May 3, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

I have made out the charred plastic and used a new cable lug...:facepalm:

jeffersondodson561 · May 3, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

No you can do it on the trailer with water flushette

SST1 · May 8, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

So, we have messarued yesterday...

high pressure 7A
low pressure = oil pump???
there is only a mechanical pump...

we measured also with an oscillator and found out that we have voltage fluctuation in waveform...from 8.1 up to 12.2 V

voltage drops, amps go up and vice versa...

we think its the alternator...

jeffersondodson561 · May 8, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

Post your serial number, you have a PM

The mechanical pump can be referred to the lift pump in this scenario:

SST1 · May 9, 2011

Re: Problems with main fuel pump relay on 225 Opti 2003

PM sent!

pcuttle · Jul 30, 2012

Re: Problems with main fuel pump relay on 225 Opti 2003

I am having the exact same problem on my 2003 200 HP Opti. Any suggestions on what fixed the problem or what may be wrong would be greatly appreciated! I have already replaced the charred wiring and harness connectors hoping the problem may be related to dirty connections creating too much resistance and thus enough heat to burn up the relays.

Again, any help would be appreciated!

SST1 · Aug 4, 2012

Re: Problems with main fuel pump relay on 225 Opti 2003

hi pcuttle,

we had done many things...

at the end...the connecter (where the relay is pressed in) was the wrongdoer...

we removed the connecter and seized the cables direcly with the relay...

now sinc 80 hours no problem...

Problems with main fuel pump relay on 225 Opti 2003

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