Glow plugs

[Yellowdog]

New here, I just bought a 94 2500 GMC with the 6.5 turbo diesel. Having issues with cold start. I did a search and it looks like the most common advice here is to replace the glow plugs. I was told not long after I bought it to put a toggle switch on the glow plugs to help with the cold start. This truck will be parked a week or longer at a time without being able to plug in the block heater.

I did some testing and there is 10 volts at the glow plug can I just wire them direct? Or is there a better way?

[a5150nut]

Might want to test the Glow Plug Relay first.

[Yellowdog]

Is there a how to somewhere I can read? Where is the relay? This is my first diesel.

[trbankii]

The post four below yours - no start/hard start - has instructions for testing the glow plugs.

[a5150nut]

Is there a how to somewhere I can read? Where is the relay? This is my first diesel.

There is a search feature near the top of screen

Should be located in the middle of the valley just in front of the firewall. Black molded object with wires connected. Just follow glow wires back to it. Don't remember exact volts and resistances but again Search feature will lead you to the answers.

You can add more info about your truck to your signature and it will help us here to help you better.

Welcome to the best 6.5/Duramax forum there is

[Yellowdog]

Thanks guys I'm going out of town Tomorrow so I will look at that when I get back I'll keep you in the loop.

[tractorwilly]

I was told not long after I bought it to put a toggle switch on the glow plugs to help with the cold start

Welcome. I am also new here and would like to share my glow plug experience.

I opted to replace glow plugs with the Bosch Duraterms. The left side is a breeze to replace once you remove the wheel. I removed wheel, inner fender and turbo downpipe on the right side and just had to use long forceps to remove and replace plug wires on 6&7.
A good ohm meter to test plugs resulted in 6 of the eight being dead or low resistance (below 1.0) resulting in my poor cold starts. Now my cold starts are perfect and relay holds for adequate time and cycles according to outside temp. Best move made for Canadian winters.. I dowsed plugs with PB Blaster every night for a few days in advance to allow penetration and the plugs came out with little to no effort.

Good luck and keep us posted

Willy