Urgent help needed. 2013 GMC 2500HD, broken down in Brazil

[alanymarce]

So, way closer to Porto Alegre than Boa Vista. Lots of infrastructure in Porto Alegre. Sounds as if progress is being made. If Mike needs more help I'll contact an overlander I know in Brazil who could do some checking in that area. There are a lot in the city, the key will be to identify the best.

 

[Martyn]

So, way closer to Porto Alegre than Boa Vista. Lots of infrastructure in Porto Alegre. Sounds as if progress is being made. If Mike needs more help I'll contact an overlander I know in Brazil who could do some checking in that area. There are a lot in the city, the key will be to identify the best.

I’ll keep everyone update. It looks like Mike pulled the relay and fuse box today to test it and look for issues like corrosion or bad connections. A member sent me the electrical manual for his vehicle that I have passed on to Mike, he is very grateful for everyone’s assistance.

If he needs more specialized help I’ll reach out.

 

[Martyn]

Latest update:
Well the relay and fuse box is a little corroded. We suspect that the power train relay is not sending power to the throttle position sensor. When we do a work around with power to that fuse the engine runs. There is something broken in the fuse block since it’s not the relay (we have tried several others and still the same problem. Essentially we can get the relay to click but it some how is not providing power to fuse 5 ( throttle position sensor). When we provide power from another fuse to the fuse 5 it starts and runs.“

As we all know when it rains it pours. “So tonight when I was running the engine the fan attached to the water pump came off and flew into the radiator and blew a hole in the radiator“. The good news is they can get the radiator and fan fixed.

 

[Martyn]

Currently Mike has diagnosed the problem as a bad fuse box. They have a work around to get the truck to running, but a new fuse box is the answer.

 

[alanymarce]

Progress - good news. Presumably they can by-pass any of the relays ("hot wire" fix), and (although obviously it's not exactly a good idea in general terms) by-pass the fuses. At least this would allow them to get somewhere more convenient.

 

[Martyn]

Progress - good news. Presumably they can by-pass any of the relays ("hot wire" fix), and (although obviously it's not exactly a good idea in general terms) by-pass the fuses. At least this would allow them to get somewhere more convenient.

I think that something along those lines are planned. They can always put an inline fuse on the circuit that they bypass. I haven’t had an update today from Mike, he must be reading the electrical manual, taking things apart, and wishing he had paid more attention in his high school physics lessons ?

 

[Martyn]

Great news from Mike this morning. It seems the Overland community pulled together and help sort out the issues.
”We had a some great news today. The issue is in the internal connections of the fuse block. After lots of testing we discovered that the connection on the circuit board was broken between two pins of a relay. That relay sent power to the Throttle Position sensor. The relay is fine and the fuses are fine. But no power to the TPS circuit. Thanks to an amazing person in the Netherlands who loves tracking these little gremlins down. We traded emails and texts for three days hammering at this problem. After we wired power past the broken connection we were able to run the motor and HAVE NO CODES. All the communication codes disappeared. Fortunately we found this issue because all the associated parts (except a new fuse block)in the world would have fixed nothing.

So now it’s onto fixing the radiator and fan. It appears as if the water pump still works. Thank you so much for your assistance and support. The electrical Diagrams obviously helped tremendously.”