Another electrical issue

[TruckA]

Hey,

Like this thread, http://nissandiesel.dyndns.org/viewtopic.php?t=1863, I figured I'd ask to see if anyone had pointers before diving into the harness. My glow plug system went kaput a few weeks ago so I put in an additional switch connected to a relay to bypass the glow plug system until I get around to fixing the stock system. Before it blew out, it would blow the fuse connected to it and I guess it just had enough of that. That's not my current problem, but I wanted to put that out there as background info.

Here are my current issues. The other night when coming in, I was on the highway coming home and getting off onto an exit, my dash gauges, egt gauge, voltmeter and oil pressure gauges all stopped working. The cluster and center oil and volt gauges are still illuminated, but do not work as well. Also, the key will not turn over the starter. When the gauges stopped working on the way home, I stopped to check the oil level just in case, and it was fine. Luckily the engine was warm enough that I was able to pop the clutch to start the engine, and after that I went straight home! All relays and fuses are fine, so now the search begins. Anyone have an idea of where to start?

Thanks,

David

[asavage]

Hard to venture guesses from this side of the continent, but I'll try.

Looking at the instrument cluster schematic and the starting system schematic, I think you have a faulty Ign. Switch, or possibly melted wiring on the Ign. Switch pigtail (the wires from the Ign. Switch to the first connector: 97M). I've seen both on 720s. You only get the melted wiring problem as a symptom of a excessive current draw somewhere else (aftermarket fog lights, audio "upgrades", etc.), and that might tie in with the GP system blowing fuses.

Which GP fuse was blowing, No. 4 or No. 5?

Which GPC control system are you running, the older Type 1 (1983 and older)?

[TruckA]

Well, the fact that you mention there should be two glow plug fuses makes me believe its been wired wrong from the beginning. When I did the engine swap, I tied the glow plug system into the ignition coil fuse on the '84 truck. And it was fuse number two on the block. The engine and glow plug system came out of an '82 Datsun. I'll pull off the steering column cover and check the ignition switch and other plugs when I get back home today. Thanks for the tip on where to start.

David

[asavage]

The later Type II glow plug system (1984-on) uses two fuses, one of which is just on the dash glow lamp. There are two fusible links too.

The earlier Type I glow plug system (through 1983?) has only the one fuse and two fusible links.

[TruckA]

It was the ignition switch and I have a temporary fix until I find another stock switch. I dismantled a WRX for a car project and wired its ignition switch in place for the time being.

David