loss of fuel pressure + fan fuse melted box

[gates98]

went for a ride today and after bout 2 hours of having a blast the trooper just started running really ruff wouldnt except any fuel and it just shut off check fuel pressure it was under 20 psi and went to check fuses and the fan fuse actually melted the the wire and the fuse without blowin the fuse so i towed it home started messin with it i pulled the fan fuse out and turned the key it fired right up lokked at the fuel ressure it was bout 62 psi put the fan fuse back in the fan worked but the fuse and the realy and the white wire gets really hot like its shorted out any ideas on how this would have made me loose fuel pressure or wha could be the problem in general

[Kinarfi]

went for a ride today and after bout 2 hours of having a blast the trooper just started running really ruff wouldnt except any fuel and it just shut off check fuel pressure it was under 20 psi and went to check fuses and the fan fuse actually melted the the wire and the fuse without blowin the fuse so i towed it home started messin with it i pulled the fan fuse out and turned the key it fired right up lokked at the fuel ressure it was bout 62 psi put the fan fuse back in the fan worked but the fuse and the realy and the white wire gets really hot like its shorted out any ideas on how this would have made me loose fuel pressure or wha could be the problem in general

I've this several times in 12 v and 110 and 220vac. My theory on it is that a slightly connection develops some heat or corrosion which makes more heat which causes it to loosen and or corrode which makes more heat which........... until you generating enough heat to melt everything but not pulling enough power to pop the fuse. I just finally quits making contact.

Kinarfi

[gates98]

I've this several times in 12 v and 110 and 220vac. My theory on it is that a slightly connection develops some heat or corrosion which makes more heat which causes it to loosen and or corrode which makes more heat which........... until you generating enough heat to melt everything but not pulling enough power to pop the fuse. I just finally quits making contact.

Kinarfi

any ideas on y the fan fuse would have caused the fuel pump to drop in pressure or do you think it was two separate problems ..... i guess im going to start by checkin all the wires from the fan and check all my grounds do you know how many grounds there are and where they are

[gates98]

any ideas on y the fan fuse would have caused the fuel pump to drop in pressure or do you think it was two separate problems ..... i guess im going to start by checkin all the wires from the fan and check all my grounds do you know how many grounds there are and where they are

well i check the harness from the fan to the fuse box no shorts any where the fan plug was wet so i dried it out wired everything back up and my fuel pressure would not go above 20 psi again untill i pulled the fan fuse the pressure jumped right up to 50 psi put the fuse back in and that white wire and fan fuse still keeps getting hot i dont understand how the fuel pump and the fan are connected

[rocmoc]

Place the fan & fuel pump on their own circuit. You can purchase an in-line fuse for protection at any parts house.

rocmoc n AZ/Mexico

[gates98]

Place the fan & fuel pump on their own circuit. You can purchase an in-line fuse for protection at any parts house.

rocmoc n AZ/Mexico

they are on theyre own circuit arent they there is separet fuses for each idk im just confused lol

[Jarrad]

they are on theyre own circuit arent they there is separet fuses for each idk im just confused lol

They use the same power supply.. use a relay and a inline fuse for the fan and have the old fan power wire trigger the relay.. it maybe that the power supply going into the fuse box has a high resistance in it, I would check it with a volt meter and see how much voltage is at the pump with and without the fan fuse in

[ricksrb]

went for a ride today and after bout 2 hours of having a blast the trooper just started running really ruff wouldnt except any fuel and it just shut off check fuel pressure it was under 20 psi and went to check fuses and the fan fuse actually melted the the wire and the fuse without blowin the fuse so i towed it home started messin with it i pulled the fan fuse out and turned the key it fired right up lokked at the fuel ressure it was bout 62 psi put the fan fuse back in the fan worked but the fuse and the realy and the white wire gets really hot like its shorted out any ideas on how this would have made me loose fuel pressure or wha could be the problem in general

I quickly looked at the diagram and it shows a wire going between the fan relay and the fuel pump relay.

[gates98]

They use the same power supply.. use a relay and a inline fuse for the fan and have the old fan power wire trigger the relay.. it maybe that the power supply going into the fuse box has a high resistance in it, I would check it with a volt meter and see how much voltage is at the pump with and without the fan fuse in

ok i checked the fuel pump current with the fan fuse in it was 13.20vdc and with the fuse out it was 13.75 vdc so whats this mean

[gates98]

I quickly looked at the diagram and it shows a wire going between the fan relay and the fuel pump relay.

yeah looks like they jump the power from the fan to the fuel pump

[Kinarfi]

any ideas on y the fan fuse would have caused the fuel pump to drop in pressure or do you think it was two separate problems ..... i guess im going to start by checkin all the wires from the fan and check all my grounds do you know how many grounds there are and where they are

As the connection begins to heat and self destruct, the heat is caused by the voltage drop across the connection, and as it self destructs the voltage drop get larger and larger leaving less voltage for the pump and thus the pump can't make the pressure needed.

The amount of heat is determined the voltage drop across the connection and the current through the connection, as the voltage goes up, the current will decrease, but the heat (wattage dissipated) will continue to increase up to about a 25% voltage drop and then start falling off, but the damage has probably been done by this point.

Hope this is understandable, It's doubtful you have any other problems, like grounds, but it doesn't hurt to check, real often, I have cured problems that I couldn't fine the exact cause of by just pull the fuse or relay and plugging them back in, they seem to make a better contact because of the sliding in & out. Also if you have a loose connection,you should be able to feel it.

Kinarfi

[gates98]

As the connection begins to heat and self destruct, the heat is caused by the voltage drop across the connection, and as it self destructs the voltage drop get larger and larger leaving less voltage for the pump and thus the pump can't make the pressure needed.

The amount of heat is determined the voltage drop across the connection and the current through the connection, as the voltage goes up, the current will decrease, but the heat (wattage dissipated) will continue to increase up to about a 25% voltage drop and then start falling off, but the damage has probably been done by this point.

Hope this is understandable, It's doubtful you have any other problems, like grounds, but it doesn't hurt to check, real often, I have cured problems that I couldn't fine the exact cause of by just pull the fuse or relay and plugging them back in, they seem to make a better contact because of the sliding in & out. Also if you have a loose connection,you should be able to feel it.

Kinarfi

ok thanks alot i talked to snowman yesterday and he explained how to put the fan on its own circuit ill be finishing that up today ill let you guys know how it turns out thanks again for everyones help