I have the common 'flashing buttons but no 4wd' problem on my '99 Blazer here in the UK. Everything else seems OK so I want to replace the transfer case vacuum switch. Trouble is I can't even feel it never mind see it or get a spanner on it. Anyone got any hints on how to change this part??

Thanks.

 

3-button or 4-button dash switch?

 

Hi,

4 button. Auto, 2hi, 4hi, 2lo.

Thanks.

 

You are in luck. The reason you cannot locate the transfer case vacuum switch is because the NV236 (4-button switch) does not use one. Instead, it has an electronic vacuum solenoid on the firewall near the distributor.

 

That explains a lot! Thanks for the advice; brilliant.