I just had new AC plugs installed, several were dead. Truck started pretty good when cold for a few weeks but now very hard too start, even with new block heater plugged in. It's putting out lots of white smoke so I'm assuming plenty of fuel. Lift pump working well and I use Howes for antigel. works fine after it fires up. I'm thinking maybe plugs aren't being energized athough wait to start light comes on. I'm going to change fuel filter even though it's fairly new.

My question: is there any easy way to install a manual switch for glow plugs on my 97 without screwing up other electronics or inputs or whatever. Any advice would be appreciated.

As long as you don't loose coolant, the white smoke when cold seems pretty normal; I have that, too. Most of it is moisture sucked in with the air. The moisture evaporates in the combustion chamber and condenses quickly within the cold exhaust pipes or immediately when it gets out, making a lot of white vapor. If it were fuel, I'd expect it would smell like fuel very intensively, but it does not.

Maybe you have a failing glow plug relay, but that is supposed to set an error code and trigger the SES light. You could attach a voltmeter to the plugs, one after another. While glowing, there should be about 12V going to the plug (cable +, plug -). After glowing, there's about 1.2V in the opposite direction (plug +, cable -) while the engine is not started. I don't know what you should get once the engine is running (I didn't measure that), but I've been told that the plugs are powered all the time. They're emissions related, and that's the reason why the can trigger the SES light.

If you glow the plugs too long, you can melt them or burn them out, unless you've got plugs that are desingned for extended glowing durations.

The glow plug relay has two large connectors and a plug with three smaller connections. I think the large connectors are for powering the plugs --- one of it is powered all the time, so if you decide to replace the relay, disconnect the batteries before you get at it. I've no idea how the three small connectors work, though. They flow current in only one way, so things are not exactly simple --- and the realy I have at hand is one I replaced because it failed.

Can it be that you've got faulty or false plugs installed that are already dead? Does it start better if you wait for the glow-light to go off for the second time?

Thanks Lee. There is a definite smell of fuel, waiting for second cycle makes no difference. Truck is to the point where it won't start if it gets much colder(only -7 to -10 Celcieus, 15 to 18F). I havent checked voltage at plugs, but I pulled 10 amp glow fuse this morning and tried to start, same scenario. (WTS light still functions) I then gave a small shot of quik start and she fired right up. This leads me to think The glow system is dead.

I guess I could replace the relay/controller, where is it by the way? But I would rather go to a manual switch if it is possible. I think an extra few seconds on theAC60s would be beneficial for starting.

Hm, I think 10 amps for the glow fuse is something else than the plugs. The plugs draw 50--55 amps. I'd measure at least some of the plugs --- it's easy to get at the wiring of the two plugs on the drivers side, the front ones. This would tell you if they get power --- if they don't, it may be some fuse or the relay or bad wiring.

The glow relay is installed on the firewall below the fuel filter, behind and in the middle of the block. It's hidden by the wiring harness. It's easy to replace but not so easy to get at it --- I placed a chair in front of the truck and leaned over the block.

Sorry, I don't know if a manual switch can be installed. I think it's possible and easy enough if you only can find out whitch wire must be powered. But if the plugs are dead or the relay is broken, the manual switch won't help unless you remove the relay and install your own one instead, or if you replace it. But if the relay failed and you replace it, you won't need a manual switch.

I'd guess that you could power the plugs with your own relay if you make it connecting the wires that go to the two large connectors on the relay. But then, you won't be able to supply the 1.2 volts to the plugs that should be there.

Here are some pics of the relay:

Just wire in a toggle for the CTS and cut it out when you cycle the glows. You'll get all the heat that way. just flip the toggle back when you startup.

CTS? I don't know what that is, or where to find it, but if you elaborate, I'll give it a try. Thanks for the pics of the controller, I can make it out under a tangle of wires in back. Any idea on price? My buddy calls his the $300 truck, anytime something goes wrong it's $300 to fix it! I'm beginning to believe him, but it's still cheaper than a $8-$900 monthly payment.

The CTS is in the coolant crossover. If this sensor is unplugged the glows will heat for an extended peroid. A toggle would aloow you to disconnect the CTS in cab and flip it back once it starts.

I've converted several trucks by adding an old style (i.e., GM Pt# 560580) relay in parallel with the existing controller. The relay was used on the GM 5.7 and early 6.2 engines. (looks like the old Ford starter solonoid)

The relay has two big terminals that you connect to the existing controller's large terminals (parallel, straight across from one to the other) The pull-in winding to operate the relay has two spade terminals. Hook one to Ignition 12V (hot w/key in both start and run positions) and the other to one terminal of a spring loaded momentary-on style switch of your choice. (Push botton, Toggle, Etc.) Run the other terminal of the switch to ground. (Momentary type prevents you from leaving it on, you have to hold it manually)

This system works well if you have an engine slightly worn that requires a little heat from the glo plugs even after it's warm. The glo plugs won't come on after the water temp warms up and the thermal inhibit switch opens. It thinks you shouldn't need the glo plugs, but the engine says, "Yes I do!"

You can push the button and bypass the controller to start a stubborn engine. Be mindful of the length of time you hold the switch down. 7 - 10 seconds should be plenty. You've heard all the horror stories of burned up glo plugs!

Another idea to consider is the timing. The 92 I recently got was smoking real bad on cold start and even missing if you tried to accelerate before it warmed up. Once warmed up it seemed to run fine with no smoking, but just didn't seem to have as much power as I thought it should. Talked with a good local diesel mechanic and he told me it was most likely timing. So, I had him set the timing.

Turns out mine had to be advanced quite a bit. Now it runs great! Starts much easier, hardly any smoke and has much better power. He said a lot of guys just put on new injector pumps right away when it is like that, when often all they need is timing reset.

I've got power to plugs, at least the few I checked and the lights dim when the afterglow cycles. QM, I unhooked the CTS and she glowed longer and started better. I left it unhooked for the day and truck idled higher, I guess that input cuts out high idle, it also seemed that the diesel rattle was more pronounced. Does leaving this unhooked affect drivability or economy? I'm going to put in a toggle switch as you suggested, does it matter which wire I cut into?( you have to excuse me, I'm "electrically challenged") This sounds like an easier option than a second relay. Thanks to everyone for advice.