Burning Main Fuses

[Will L.]

Misunderstood. I have NOT heard from him. Just keeping him in the prayers.

 

[MrMarty51]

Misunderstood. I have NOT heard from him. Just keeping him in the prayers.

I too pray he and family are doing well and He has found some sort of relief from the pain.

 

[dbrannon79]

Marty, those two 30 amp fuses in the rear of the box are for the two studs with all the wires attached. all of that is aftermarket additions on those studs. the blower should only draw about 25 amps at full speed. anything over that and it will burn out the resistor pack for the lower speeds and possibly the blower switch. sadly GM only used a single relay for the high speed on the newer rigs. my 93 has a relay for each speed saving all the wiring and switches from factory. IDK why they stopped doing that other than to pinch pennies.

I learned that even with a new blower, if there is too much resistance with it sucking or pushing air in the box that will increase the amperage drawn. I would vote for a new motor, but also check the evap coils and the recirc door while you have to blower out of the hole. you can actuate the recirc door with the motor out and disconnected with just the key on and pushing the max button. it's hard to see in there on the evap but can weasel your hand in there and feel around for debris. use the blow gun on the compressor in there to blow out the evap coil. it's common for the blower to suck in leaves and debris with the heat or defrost running. all that air comes from under the wiper cowl.

 

[MrMarty51]

Marty, those two 30 amp fuses in the rear of the box are for the two studs with all the wires attached. all of that is aftermarket additions on those studs. the blower should only draw about 25 amps at full speed. anything over that and it will burn out the resistor pack for the lower speeds and possibly the blower switch. sadly GM only used a single relay for the high speed on the newer rigs. my 93 has a relay for each speed saving all the wiring and switches from factory. IDK why they stopped doing that other than to pinch pennies.

I learned that even with a new blower, if there is too much resistance with it sucking or pushing air in the box that will increase the amperage drawn. I would vote for a new motor, but also check the evap coils and the recirc door while you have to blower out of the hole. you can actuate the recirc door with the motor out and disconnected with just the key on and pushing the max button. it's hard to see in there on the evap but can weasel your hand in there and feel around for debris. use the blow gun on the compressor in there to blow out the evap coil. it's common for the blower to suck in leaves and debris with the heat or defrost running. all that air comes from under the wiper cowl.

That I shall do.
Seeing that the blower high speed is on that 50 amp fused relay circuit, I’m thinking that maybe the plug/harness on the back of the speed control switch may have some burned insulation and possibly some cross wiring happening.
But I also think that even the high blower speed 50 amp circuit is still possibly fed through the lower speed circuits.
The wiring diagram in my book just shows thise wires, and many others, all going into one block, rectangle image, on the page.

 

[MrMarty51]

Anyhow, NAPA got the wrong blower so proper one will be here today, Wednesday, in the morning shipment from Billings.
When I called NAPA a week or so ago, counter man told me it was not listed in their catalogue, okay so I hung up.
Monday I calked the Chevy dealer, he had two possible part numbers, NAPA man looked them up, one was the okd single terminal, other newer one didnt look right but still had the dual spade terminal except on the end of wires instead of out of the motor prompt. Figured okay, change in design. WRONG