Blowing instrument fuse

[dizzydee]

I have a 1987 chev van that blows the 20a fuse for the instrument guages occasionally. It ussually happens when I have run the van for a few minutes and shut it down. When I start it up again, the guages go funny (oil pressure guage wraps around - giving the impression of zero oil pressure, fuel guage goes wonky, etc.). It is a pain in the butt as I have to pull the dash apart, flick the oil pressure needle back to where it should be. With the fuse replaced, everything is fine (until the next time I forget and run for a short period and shut down...).

Any ideas?

Thanks!

[nape]

Same sort of problem,
My son and I just changed engines in a 87 sub. The guages keep blowing the fuse. I can find no short but it seems every time you crank it and rev it up it happens. I put in a 30 amp breaker and solved the problem but it still seems to be there. The volts seem to go low occasionally like something is drawing a lot of amps. I have no answer but would like to hear input. I have found no apparent short in the system.
Wayne

[GreasySub]

I'm new the The Diesel Page and am looking for a solution to a similar problem. I have a 1990 Suburban 6.2 (180K miles) and for the past few months the dash gauge fuse will blow periodically. However, when mine blows, the glow plugs don't function either (hence no cold start). I have only unplugged and replugged various glow plugs and disconnected and reconnected the relay and it will work again.

Recently the problem became more frequent until now I can fiddle with the glow plugs, replace the fuse, cycle the plugs, and start the engine, but as soon as the engine starts, the fuse blows. It also blows immediately if I replace while the engine is running.

Does this make any sense to anybody?

[john8662]

Electrical Gremelins...

Time to check for some chaffing of the wiring for the gauge problem.

Things I'd check..

Connections at or near each sender associated with the gauges.
Connections behind the instrument cluster

For the glow plug problem, check the connections at the controller, or replace the controller.

[GreasySub]

Thanks for the suggestions. I had to leave town and won't get to it till next week. However, it appears that the two problems are directly connected. Is that possible? It seems that the glow plugs are blowing the gauge fuse.

[NH2112]

Try unplugging the fuel heater, if it's shorted it'll often blow the inst fuse.

[GreasySub]

Thank you for the suggestion. Forgive me, but I still have a lot to learn about diesel engines. It the fuel heater tied in with the fuel filter or is it somewhere else in the fuel line?

[GreasySub]

Thanks for the fuel heater suggestion. I finally got some time to work on it. Unplugged the heater and everything else worked fine.

[NH2112]

I'm happy to hear you found the problem. If it gets below 30 or so regularly, you might want to replace the heater to eliminate fuel gelling in the filter. Although, I haven't run a heater in 3 years and never had a problem even at -30 or so. The fuel at the pumps is supposed to be blended so it doesn't gel at the expected low for the area, but you never know!

[GreasySub]

I just moved from Nebraska to North Texas. I'm not expecting an abundance of days below 30, but I'm sure they'll be some. Thanks for the help.