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starting problems

Posted: Wed Mar 06, 2013 12:35 pm
by mongrel
Hi All,
I'm new here and need your help. I have an '84 kcab with an sd22 replacement engine. (bought it that way). I'm assuming that glow plug system is from the '84 but don't know for sure. I have wired an led to the rear glow plug so I know exactly when the GP's are on. (Learned this from my old ford ps- but that's another sad story)
The symptoms are when I turn key to "on" GP's come on like they should most of the time. If I turn key off then back to "on" the GPs just blink on for split second then nothing. My remedy was a push button on the dash and 80A relay independant of the stock system. The truck still won't fire up.
It looks like I need new glow plugs for sure, but would bad plugs cause the system to "blink" or would bad stock relay? Any thoughts?

ps: the injection pump controller works but is not hooked up because of bad dpc. I shut truck off with dash cable. :?

Posted: Wed Mar 06, 2013 6:39 pm
by Nissan_Ranger
Hello and welcome.

You need to actually check amperage draw on the glow plug feeder circuit one at a time. Make sure gp connections are clean. The following may be of interest...

http://nissandiesel.dyndns.org/viewtopi ... +glow+plug

http://nissandiesel.dyndns.org/viewtopi ... +glow+plug

http://nissandiesel.dyndns.org/viewtopi ... +glow+plug

Regards,
N_R

Posted: Mon Mar 18, 2013 1:16 am
by Kay Nickerson
:o Nissan SD 22 GP are wired in a parallel circuit, AKA current divider; adding an LED will change the entire resistance and current flow to each GP, but as that happens one GP will draw more current (i.e. opens or shorts) and then the domino effect takes place whipping out the rest of the GP's over a period of time. That's why these GP's are replaced and often sold as a 4 set.
Hope this helps.

Posted: Mon Mar 18, 2013 6:41 pm
by Nissan_Ranger
I can't agree with that. The miniscule loading of an LED will not affect the circuit in a measurable way and the current dividing circuit effect you describe does not apply to the SD-22 in a meaningful way due to the fact that there is no ballast in the GP circuit.

N_R

Posted: Tue Mar 19, 2013 6:27 pm
by 5and2dimes1
I have an extra dcp. Do you want to buy it?