Known fuse box overheating and melting fuses?

[Steven Almendarez]

1991 model had intermittent no crank, so I verified with the service manual that the cam sensor was bad. Drove it a couple times and then crank no start. Fuel pump was seized up, replaced it and only getting 6V to fuel pump. Couple weeks later, three melted fuses, after a different guy was tinkering with it, while replacing the fuses and verifying the others were correct and in good shape I found some were in the wrong spot. For example, the cluster fuse _5A_ , had a 20A . the owner said he was told something about a common problem of the contacts in the fuse box had a thinner gauge of metal used in them that heated up and caused electrical issues?
Anyone ever here of a problem with the fuse box heating up causing a reduction in voltage to the fuel pump causing a crank/no start?

 

[SHOdded]

Welcome! I assume you are fixing the SHO for someone else? Are they the original owners? I ask because many times instead of fixing the problem, people put in incorrect rated fuses to "get by". That plus the aging wiring is a bad combo.

 

[sperold]

There is no fuse box issue that has been established. There are 2 fuse boxes, one under the hood and one under the dash. Neither one is problem prone.

You might want to report how you determined the cam sensor was a problem.

First step is always read the codes that have been stored, and they do not necessarily illuminate your Check Engine Light (CEL).

 

[Steven Almendarez]

Welcome! I assume you are fixing the SHO for someone else? Are they the original owners? I ask because many times instead of fixing the problem, people put in incorrect rated fuses to "get by". That plus the aging wiring is a bad combo.

There.is some aftermarket tow behind lights because the second owner used to pull it behind an RV, a lot. I figured I was gonna have to chase that wiring and remove it, then repair whatever it had damaged

 

[Steven Almendarez]

There is no fuse box issue that has been established. There are 2 fuse boxes, one under the hood and one under the dash. Neither one is problem prone.

You might want to report how you determined the cam sensor was a problem.

First step is always read the codes that have been stored, and they do not necessarily illuminate your Check Engine Light (CEL).

I can't remember what the code was, but when I finally bought the factory service manual, I used the diagnostic flow chart to test the cam sensor.
I figured the fuse box wasn't the problem, so I was just checking if anyone had a similar situation.
What baffles me the most is only getting 6v at the fuel pump. My next step is tracing all of the after market tow light wiring. And then retest the circuit for good power and good ground with a voltage drop test.

 

[rubydist]

I have seen opens and shorts in the harnesses themselves, so its not that hard to get enough voltage drop to have only 6V at the pump. Of course, it would not take long to ruin the pump at 6V.

 

[Steven Almendarez]

I have seen opens and shorts in the harnesses themselves, so its not that hard to get enough voltage drop to have only 6V at the pump. Of course, it would not take long to ruin the pump at 6V.

So, you're saying it should have at least how much voltage