Could someone please explain how long glow plugs come on for, when starting? Do they stay on for two minutes or shut off when "wait to start light" goes out? When I read about cycling the plugs are guys waiting for two minutes, or for "wait to start light" to go off, before clicking off and on again?
If anyone remembers a link to a post on changing glow plug relay I sure would like a copy of it, thanks again for all the info!

 

Chiltons says the on time varies between 1 and 120 seconds. The wait to start lamp goes out when the glowplugs are hot enough to start the engine. Its a little vague but it says the wait lamp comes on when the ignition switch is in the On position, only when the engine is below 165'F. It also says for a bulb check, the bulb will come on when the ignition switch is in the Start Position.

Here is a good link is a good link that might help you out.

http://andersonimprovements.com/hobb...sandrelay.html
Jim 1999 F305 PSD DRW 4x4 manual. 120,000mi

 

Mopey, the length of time the glow plugs stay on is actually not related to how long the WAIT TO START light stays on (go figure!).

Glow plug relay operation:

With key off you should have battery voltage to one large terminal and nothing to the other large or either of the small terminals.

With key on for the first two minutes or so you should have battery voltage to both large and one small terminal. The other small terminal should show ground. This shows the relay active.

With the key on and after the glow plug cycle has finished you should have battery voltage to one large and both small terminals. The computer activates the relay by grounding the second small terminal thus activating the relay.

It is possible to have battery voltage to both large terminals when the relay is active and still have a bad relay. If the contacts inside are pitted or corroded you may have low amp voltage passing through it but not enough power to actually run the glow plugs.


MrBeechwood has linked you to an excellent article on the glow plug system. I have used it several times and post it any time I run across a question on the glow plugs or relay. If you would like, I have this article saved as an MS Word document with a couple minor updates along with my experience when I did mine a few years ago. If you would like me to send them to you as an attachment, send me an eMail through the site with GLOW PLUG INFORMATION as the subject and the eMail address you would like me to use. I will reply with the attachments.

Dave / Believer45

 

Thanks for the info guys, I cannot email through site yet but I have the article through MrBeechwood's link. Good Info thanks Alot.

 

Mopey, you have eMail at the address you listed here on this site. If you will reply to me I will send you the attachments I mentioned earlier if you want them.

Dave / Believer45