I've always had small problem with my instrument gauges fluctuating on my '67 Barracuda, (oil pressure, fuel level, engine temperature), but only in small increments, and I've just ignored them until now.

It's been over 100 degF in Portland the last couple days and the gauge fluctuations were kind of wild, especially my temperature gauge. I drove to Mount Hood to get away from the heat--a mild 90+ degrees there--and the oil pressure and fuel level gauges were both higher than normal, but my temperature gauge began to approach the H before I got out of town, so I pulled over--note: I just installed a Stant SuperStat 180 last week--and there was not even any pressure in my top radiator hose, so I opened the cap, which was hot, and the coolant was full. The heater also was blasting hot air. Everything seemed normal.

I made a phone call to a friend who is a MoPar guy, and he said he's always had these sorts of problems on the several Barracudas he's had over the years. So I continued driving. The temperature gauge pegged to the H, and even a bit beyond, (oil and fuel gauges high as well). Everything still seemed OK, no over-heating.

I eventually did over-heat a bit, but on the 5-mile stretch of 6% grade up to the mountain at 100 degrees, I think I would have regardless, and it was just a bit of a gurgle from the overflow hose at the cap. So we stopped at Government Camp for lunch and a cold beer, topped off the radiator, and continued to the lake for a campsite.

Once at the lake, I lost all electrical power at my dashboard: fan, radio, blinkers, and all gauges--except AC/DC. This is after a brutal 90 minutes of driving up 5000 feet or so, including one lunch break, in 100 degrees. So I opened the hood for only a couple mintues and looked at all the wires and such. Nothing looked fried or anything. I got back in the car, real frustrated, and turned the key on, only to discover that not only did I have my dashboard power restored, but all of my gauges seemed to be working perfectly! The fuel gauge went down to about where I'd expect, the oil pressure was just south of the middle, and my temperature guage was 1/3 from C! That didn't last, however, and the gauges resumed insanity, including all the way back home a couple days later--though I never lost dashboard power again.

Any explanation will be appreciated.

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1967 Barracuda 225

Nice looking yellow Cuda!

Voltage limiter may be sticking open or closed, causing problems with fuel & temperature gages, but that dose not explain oil pressure problems.

Have you checked the connections at the temperature & oil pressure sensors, and where they pass through the bulkhead connector. Another spot to check is the condition of your circuit board behind the gage cluster. Look for cooked & corroded connections, and bad grounding.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Thanks!

Where/what is the voltage limiter, and bulkhead connector? (Electronics are my weak spot). I have yet to crawl under the dash to check the wires. Also, where is the oil sensor at? I think the temperature sensor is by the thermostat housing...

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1967 Barracuda 225

The voltage limiter is built into the fuel gauge,the fuel,temp,oil gauge are all controlled by this limiter.

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V8?? We don't need no stink'n V8!!

Does that mean it is located (attached) behind my instrument panel at the fuel gauge?

It seems hot weather affects the functionality of the instrument panel. When I take my car out in the morning when it is cool, everything is fine; the temp is about 1/3 from C, and the oil pressure stays near the midline, (I don't put too much credence in the fuel gauge after running out of gas a time or two). When it heats up outside (90 to 100 degrees), things start going haywire. Any takes on that?

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1967 Barracuda 225

See page 5 on this electrical forum.Last posted jan.25 2009. "where is the volt limiter on 67 panel" And yes the VR is inside the actual gauge,that's why you don't see it.

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V8?? We don't need no stink'n V8!!

1967 Cuda: Voltage limiter is housed within the fuel gage on your Cuda; its job is to reduce 12 V to 5 volts to power the gages. A limiter is a set of points that operates like the voltage regulator on your fire wall.

Bulkhead connector is the rectangular Bakelite wire connection point on the fire wall left of master cylinder and down a bit, where on the engine side, there are three caps with up to ten wires each that pass through to under your dash. On the dash side it is just a single unit with spots for thirty wires. Is just to the right and up a bit from the gas pedal. This connector contains brass male/female connectors that can become corroded over the years; increasing the electrical resistance which will produce heat.

Oil sensor is located below the oil filter on the oil pump facing the firewall. One wire connects to a threaded stud centered on the sending unit where it travels to the bulkhead connector through the fire wall and on to the oil pressure gage.

You are correct, the temperature sensor is near to the upper radiator hose housing. It to has only one wire connecting to a centered stud which passes to your temperature gage.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Ok, I remember checking that. There is one fairly heavy gauge wire on there that has a fuse on it. I opened it, and the fuse looked a bit tired, but not broken; what could that be for? I'm still wondering why I lost all power, but regained it after fiddling with that fuse, and wiggling the other wires a bit.

Thanks!
Thomas

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1967 Barracuda 225

1967cuda:

Is this device you are referring to indicates charge & discharge? If so, it is the amp gage.

Would that wire with a single fuse be; 10 gage (heavy) and red?

If so, that red wire passes from battery to starter relay, to fusible link (old style "over current protection") and most likely where your single fuse resides replacing that link, through the bulkhead connector to the amp gage; from there it turns black, feeds the ignition switch, headlight switch, fuse block, etc. If that circuit were to "open" or no longer be completely connected, your car would lose power to most devices.

Chances are good where that red wire passes through the bulkhead connector; is where some of your problem resides. Carefully inspect both sides of this connection, engine side & under dash, looking for heat damage. You may have to carefully pull off the ten wire cap on the engine side of the connector for a good look.

Crusty, burnt, melted, stiff or brittle insulation indicate you need to clean these connections, and or perhaps replace the brass, and all damaged wire with like materials. You have had a warning with your recent black-out. The problem is going to grow if not addressed soon, provoking the Fire Gods.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Just some advice if you remove the wires at the ammeter - the nuts seem to get welded in place and are often *very* hard to remove. It is easy to force them and end up rotating the ammeter stud, breaking the ammeter. If they don't come free easily, you're far better off carefully cutting the nuts off than breaking the ammeter.