So today, I'm driving to a job site and I notice that my oil pressure, fuel, and temp gauges are all "dead." Then I noticed that the heater fan blower swith/knob also doesn't work. Everything was working fine about an hour before, and the fj40 still was running fine, etc. I thought a fuse blew and looked at the fuse box. All the fuses seemed to be perfect. I checked for loose wires etc. but after a quick look, found nothing out of the ordinary.... Any ideas what to look for and/or where to chase this down? Are there more fuses somewhere or something?

Thanks a lot and happy holidays

JR


'78 fj40

sounds like a ground to me....check that the ground between the battery and the frame/firewall is in good shape.

You can test with a temp wire too....just connect from ground to the dash insert and see if things start working again.

corrosion...yee hah! lol

Woody, Thanks for the advice. Sorry for this newbie lack of knowledge, but what is "...the dash insert..."?

Do I need to pop out the gauge cluster?

Thanks again,
Jim

yup-check your ground. or check any cheesy crimped on splices

gauge cluster, dash insert

potato, potatoe

tomato, tomatoe

yer face, yer ass

...ya get the idea...lol

Grounds are a common issue, one bad crimp, one loose connection, one bit of corrosion, and all hell can break loose...or, as you've notice, NOT break loose...

Not trying to be contrary, but this is not likely to be a ground issue because all these things (like the oil pressure, heater fan, fuel gauge, etc) have separate and independent grounds and it would have to be a rare coincide for all of them to be bad at once. A more likely culprit is the main feed wire to the fuse block or the fuse block itself.

good point...these items are all part of a switched current too...perhaps a loose connection on the back of the fuse block? Perhaps a lost connection at the keyswitch?

The only thing I hate worse about diagnosing electrical gremlins over the internet is doing it in person :flipoff2:

I agree with Pin head and I have had this problem before, it my case it was the fuse block. I found that I could wiggle the fuse block and get it get the guages and blower working again. On older trucks the fuse block is replaceable but one new (I think 79 and newer) it is not. If I recall, it was a piece of sheet metal formed onto another and it was corroded.

When I replaced mine 10 years ago it was $22.00

-Stumbaugh

I've had rusty contacts with the fuse ends produce similar results. Just spinning the fuses in place would sometimes correct it, until the corrosion built up again. I would clean the contacts with emory paper, which also helped a little. Finally just replaced the damn thing.

Wow! It's snowing a lot now! Thank you all for your advice, I'm going outside now to try to fix/find the problem. It is strange that the lights, speedo, and am-meter work fine. Lighter, glove box plug, temp, fuel, and oil press. gauges are dead...Hmmm. I'll check all the areas you've all been so kind to suggest.
Thanks!

JR

It is not surprising. Knowing what still is working is just as important in diagnosing the problem. It means that your heater and cigarette fuses are bad or the connections for these fuses in the fuse box are corroded. The other fuses and the feed to the main buss bar in the fuse box are OK.

Well, I just went out there and moved things around at the fuse box and pushed on it and then the stuff worked again. I didn't actually pinpoint it, but it's working again so I'm happy. I noticed many of the fuses had rust/corrosion inside of them, so I plan to replace those too.

Thanks all,
JR

A stainless steel wire brush about the size of a toothbrush can go a long way in fixing your problems like yours. I buy them by the dozen at the welding store for about $3.oo each. They work great for fixing bad electrical connections.

Scape off what you can with a knife and then clean it up with a wire brush.

A stainless steel wire brush about the size of a toothbrush can go a long way in fixing your problems like yours. I buy them by the dozen at the welding store for about $3.oo each. They work great for fixing bad electrical connections.

I bought some brushes at Wal-Mart, kind they use for cleaning gun barrels, available in your favorite caliber.

John

my friends FJ40 did that all the way through rubicon , would hit hard or get a little moisture behind fuse block and everything would work except starter circuit , push on it and generally f- with it and presto she would fire right up , funny little habbit cruisers have I guess

Originally posted by 4Cruisers


I bought some brushes at Wal-Mart, kind they use for cleaning gun barrels, available in your favorite caliber.

John


I use those for the cleaning the nozzle on my mig welder - 12 guage works well for the large miller gun and .45 or 410 guage works well for the small ones...

Got to love finding stuff that you can use in the garage.

-Stumbaugh