[Crimedog]

My intake grid heater is acting up. Here is what happens: The temp is around 40 degrees, and the heater cycles for 8 seconds, and the truck turns over a lot longer, and doesn't really want to start. I can watch them draw voltage, so something is working. I can also hear the relay click. After it is started, and the post-heat cycle kicks in, I can hear the change in idle, so I am suspecting that maybe only one relay is working. What do you guys think? What is the best way to test the relays/heater? As I understand it, there are 2 relays, and the heater in intake manifold, are there one or two grids(elements)? Any help would be great. Thanks

 

[wyldman]

Sounds like your on the right track.You can test each relays output terminal (the ones going to the grids) with a test light to see if you have power coming out of both relays.If you don't,you can then check the primary side power and grounds(small terminals),and if they are good,replace the relay.Make sure you have good power on the heavy wire coming into the relay as well.

If they check out OK,you may have another problem,like rotted fuel lines sucking air.Very common,and a pain in the butt to replace.

 

[Crimedog]

When I check the relays, will there be power to the input side at all times, or just when the grid heater is activated(wait-to-start light)? I'll probably just use a volt meter, how many volts at output? (I'm not that much of an electrician:headwall ) Thanks

 

[John DiMartino]

Matt,does the truck run rough when it finally starts? If the grid heaters are working,Id look real good at the fuel return line.They crack and leak over time,and then air gets in and it looses it prime overnight after sitting.

 

[Crimedog]

The truck runs fine when it is started. It idles smooth, and hasn't seemed to lose power. I am hoping it is just the relay. After thinking about it, when I hooked up to the wrong wire for my mystery switch, I am wondering if I might have got the heater wire, because I could watch the voltage drop about 3 volts. If they are desiged to turn off (post heat) at over 19 mph, and I turned them on manually, hopefully I popped a relay. Sound like a possibility??