Glow Plug Question

[SolarSteve]

Last July I swapped out the head on my 1.6 and ever since then the GP coolant temp sensor hasn't been right.  So I disconnected the plug and just count when I glow the plugs.

The engine has been running great and last night I drove home from work, pulled into the garage shut it down and plugged in the block heater (on a timer).  Today I decided to plug the GP coolant temp sensor plug in and give it a try.  I turned the key forward and the GP light came on for only 3 seconds and went off, I try to start and nothing but white/greyish smoke.  I tried to cycle the plugs 3 times and still nothing.  Needing to get to work, I unplugged the temp sensor, let the plugs glow for about 15 seconds and still nothing but cranking and whitish smoke.  The air temp was 41F and the 400 watt block heater had been plugged in for 4 hours.  So I had to drive the truck into work.  I have not yet had a chance to start to trouble shoot this.

I am wondering, could I have burned up the relay?  The 50 amp fuse is not blown.  Is there a way to bench check the relay?  The GP's were installed in July when the head was changed and have been working all along even in the 15F nights we have been having, which makes me think its the relay.

Any ideas would be helpful

Thanks

[SolarSteve]

Oh yeah, I took a quick peek under the timing belt cover and the belt is on and tight.

[burn_your_money]

If you have power at the glowplugs then the relay is working.

[8v-of-fury]

try giving the buss bar (that connects all four gp's) 12v's for 10-15 seconds with a jumper cable from the battery and see if it will make a difference then.

[trev]

I've been told that the sensors are different, but they are the same part in my car.

Swap the leads between the two sensors. they use the same connector. If they are supposed to be different, you may have them swapped around.

I'd try it, anyway. Cheap and quick check, like under a minute.

One of my sensors is dead, so i chose to have a glow plug relay, rather than a temperature reading on the dashboard.

 Cheers
  Trev

[SolarSteve]

try giving the buss bar (that connects all four gp's) 12v's for 10-15 seconds with a jumper cable from the battery and see if it will make a difference then.

If I do this and it starts, This is telling me that the GP's are good, and if so then where do you think the problem lies? 

[SolarSteve]

If you have power at the glowplugs then the relay is working.

OK, I'll check this when I get home.  If I have power to the plugs, but it still doesn't start, whats next.

Also, if I don't have power I will put the ohm meter on the fuse (it is intact).  If the fuse is good does that mean the relay is shot?  Would the GP light come on if the relay is bad?

Thanks

[8v-of-fury]

If I do this and it starts, This is telling me that the GP's are good, and if so then where do you think the problem lies?  

Somewhere between the battery and the Gp's.. lmao! well it could be in a number of places.. have you considered "pimping" your plugs?

http://vincewaldon.com/index.php?option=com_content&task=view&id=30&Itemid=28

[SolarSteve]

Yes I do want to pimp the plugs, but right now I am trying to buy a 1997 Dodge Ram diesel and if it happens I will be selling the Jetta, so I kind of didn't want to put the time and money into it right now.  As it was the system was working as advertised and I didn't want to fix what wasn't broke.  Too bad I didn't remind myself of that a few moments before i had the great idea of plugging the connector back in!

[8v-of-fury]

well it won't sell to good when it can't start

its a simple cheap fix. you don't have to do the whole thing. Just the switch and starter solenoid part.. you don't have to do the 4 fuses and separate wires ordeal. just take the buss feed wire and have the relay fire that, it will be good to go.. and cost maybe $20 and half hour of your time

[SolarSteve]

Is that basically bypassing the stock relay?

In the meantime, I would really like to get this problem fixed.  If I don't get power at the GP buss bar with the key forward, does that lean towards a shot relay?  Can I bench check the relay to make sure?

By the way, thank you for the replies!

[8v-of-fury]

Is that basically bypassing the stock relay?

Yes it is bypassing stock controlling of the glow plugs completely, you will control it all with a switch on the dash. Since you've already been doing it.. it won't be much different. lol

Can I bench check the relay to make sure?

Sure can! take it out.. apply 12v to one of the big spades, and a ground to the other and see if it clicks. if it clicks, then apply 12v to one of the small spades, and measure to see if you get 12v at the other small spade. if you do and this all checks out.. relay isn't the cause.. however if it doesn't click there like $50... so pimping is a lot cheaper.. and som uch easier to diagnose

[SolarSteve]

OK.  Thanks again for the help.  When I get home tonight I will start some troubleshooting and see where it gets me and I'll report my findings tomorrow.

[745 turbogreasel]

try giving the buss bar (that connects all four gp's) 12v's for 10-15 seconds with a jumper cable from the battery and see if it will make a difference then.

Also, if you do this, and there is not a trace of a spark as you hook it up, pretty much for sure no glows are working at all.
But arc your jumper to ground to be sure it  is sound before you give up on em.

[ToddA1]

Most online suppliers sell the same sender for both the GPs and the gauge. 

My relay was bad, and I replaced it with a good relay.  I'm lazy, and didn't like cycling the GPs several times with the key.  I took the cover off the old relay, reinstalled, and just hold the contact closed for about 10 seconds.

I am planning on doing the correct way, though.  I bought some new Duraterms, and some LEDs, to wire inline to tell me that the GPs are lighting.

-Todd