Community Forums

rvjimmy · 09-28-2012, 06:34 AM

Don't know the right place to post this but will try a couple different sites. My wait to start lite quit coming on. It did start after a lot of cranking and a ton of smoke, is there a relay that could go bad and where is it. Had a Ford Power Stroke and it had a relay and when it went bad it would do the same thing. I just thought if someone knows it would save me a lot of time trying to find it.

Jim

lwasouth · 09-28-2012, 07:16 AM

I may be the pressure regulator at the end of the Fuel rail in the cylinder head. If you are trying to start in moderate temperatures, glow plug won't make much difference

Tony Lee · 09-28-2012, 07:23 AM

Glow plug or air preheater?

Not that it makes a lot of difference as far as the controls go.

smlranger · 09-28-2012, 09:20 AM

CAT 3126 does not have glow plugs and uses an air intake pre heater. Not sure there is a fuse for that but check the wiring diagram for your coach and see. Or, a visit to a CAT shop.

Gary RVRoamer · 09-28-2012, 11:12 AM

Most likely a fuse or relay for the air preheat. Assuming it's a Freightliner chassis (Newmar uses Spartan too), a call the Freightliner Customer Service with your VIN should get an assist on where those are located.

1-800-FTL-HELP

Lug_Nut · 09-28-2012, 11:39 AM

It probably has a heated grid not glow plugs. They are controlled by a timed relay that is also controlled by a sensor that measures the engine heat. With the key on you should see deflection in the voltage guage showing the load it draws. By the sounds of it, your grid, relay or controller is not funtctioning. I do not know where to locate them on your coach. You may have to seek help from your OEM or a Cat dealer. Wish I could be of more help.

Peter

lwasouth · 09-29-2012, 08:07 AM

I brought up the pressure regulator because that is what happened to me. It caused a lot of cranking because the fuel rail had leaked down. I don't disagree that you have a preheater problem, but It might be both.

OneRVer · 09-29-2012, 08:16 AM

Quote:

Originally Posted by lwasouth

I brought up the pressure regulator because that is what happened to me. It caused a lot of cranking because the fuel rail had leaked down. I don't disagree that you have a preheater problem, but It might be both.

I hate to add another "what if", but, when my HEUI sensor went bad my coach acted the same way. Hard to start and a lot of smoke and for some reason my pre-heater was also acting up. I had to replace the sensor and the control valve.

rvjimmy · 09-29-2012, 05:24 PM

I was wrong on the glow plug, It is a heat grid. It must be a sensor as it starts right up when I use the engine water heater, no smoke and it runs and starts good. Just have to find out what sensor it is.

Jim

rvjimmy · 10-09-2012, 06:08 PM

Worked on my pre-heat problem Saturday. I was going to check to see if the relay that I thought might be the one was working. I had Kate go inside and turn the key on and she yelled out that the wait to start lite was staying on. So when it went out I had her start it, no smoke and ran fine, the wait to start lite came back on like it should and all was good. Went out Sunday morning, 35 degrees and it worked like it should and started right up. I don't know if I should give the DW credit for fixing it or not but it works now and I'm happy.

Jim

glenn allen · 01-06-2013, 01:50 PM

Quote:

Originally Posted by rvjimmy

Worked on my pre-heat problem Saturday. I was going to check to see if the relay that I thought might be the one was working. I had Kate go inside and turn the key on and she yelled out that the wait to start lite was staying on. So when it went out I had her start it, no smoke and ran fine, the wait to start lite came back on like it should and all was good. Went out Sunday morning, 35 degrees and it worked like it should and started right up. I don't know if I should give the DW credit for fixing it or not but it works now and I'm happy.

Jim

First things first, the DW gets all of the credit. Your HEUI pump and fuel regulators are also working. Your heating grid is more than likely the cause. I have not had a problem with mine but there should be a relay to handle the load, you may want to locate that for later. If I am correct the block temp is reported by the engine ECM and that is passed off to the light and control side of the relay. It will take longer to shut of the wait light off the colder the engine is. The control side is not as likely to be the problem.