High Blower Setting Kills Engine

[8D3]

Hey guys,new to the site.I just picked up a project 1995 Z-71 and I have been messing around with getting stuff working.I have a problem with the blower fan.It works great but when switched to high,the engine acts like it loads up and will die.No problem on any other setting,just high.Could the resistor be bad?

[bossier62guy]

Hey guys,new to the site.I just picked up a project 1995 Z-71 and I have been messing around with getting stuff working.I have a problem with the blower fan.It works great but when switched to high,the engine acts like it loads up and will die.No problem on any other setting,just high.Could the resistor be bad?

 

I don't think a faulty resistor is causing that condition....maybe a bad blower motor.

[8D3]

Thats just it,blower runs thru all speeds just fine and the voltage gauge inst eradict?I may swap it with another one just to see.

[minibike132]

Ignition switch

[8D3]

Ignition switch

 

That is a possibilty since the steering column has seen better days.But why only on high setting?

[minibike132]

Ignition switch

 

That is a possibilty since the steering column has seen better days.But why only on high setting?

 

 

 

I don't have a diagram for a 95 handy, the earliest thing I have is a 98 and it is going to be different. If this rolled into my bay with your complaint I would pull the diagram for the ignition switch. There is usually only 4 or 5 outputs for everything that is controlled by ignition power (except for new vehicles that don't really have any outputs, it's all bcm signals). So if you only have 4 or 5 outputs that means quite a few things are going to be on each output. If the blower output is on the same output as the fuel pump relay, injectors, pcm, ignition module etc. it could cause what you are explaining.

 

I would get a diagram, see which output is feeding the blower and see what else it feeds, if it's something critical then use a sealed beam to load up that circuit and do some voltage drop tests. If there is a bad contact in there it may be good enough to carry some current but the blower on high might just be enough to rob current from another circuit.

 

Same thing for the ground circuit, if it is shared by something critical and there is a poor ground it will cause the same thing.

 

W body cars were good for this, turn on the headlights and the blower stops working, turn on the blower and the wipers stop working. It was a no brainer for those because it was common. On yours I would do some testing before replacing, but ignition switch is where my testing would probably start, unless the ground is common for something critical and easier to get at.

[8D3]

How hard is it to change the ignition switch?I replaced the blower resistor since I already had it and it was no help.I did notice that the gear indicator would start flashing too with the blower on high.Im really leaning toward the switch.

[minibike132]

I'll bump ya, it's been a while since I've been under the dash of a 95 so I can't remember what it looks like or how difficult it is. Maybe with the bump someone else that knows will help ya out.