hello- i have a 99 olds alero 3.4, 80k miles. engine runs well for the most part, although subpar mpg.
the problem is that the instrument panel, power windows and ac blower are not operating. the gauges (tachometer, fuel, temp, speed) are stuck on zero, and the panel lights dont work. the hvac blower will
these symptoms first started out once a week, but now have escalated to all the time. finally, dtc codes p1665 and p1676 set (with engine check light coming on).
the stereo, courtesy lights, door locks, head lights, engine, work fine.
i suspect the problem is a bad ground, loose/poor connection, and the troublecodes dealing with the EVAP system are just symptoms of the universal problem.
tags: gauges, panel, cluster, blower, fan, dtc, codes, "service engine", "check engine light", bad, poor, ground, connection, windows, lights, dark, die, died, off, fail, stop, off,
Get a wiring Diagram. Find where the problem circuits and good circuits are different. trace down each wire and find the one that is loose that would shut off all the circuits that don't work.
I have this sort of Instrument problem on a 2005 Vauxhall (Opel) Signum 2.2 litre. The Dealer thinks it is a problem with the high speed CanBus, but cannot find an error code ..... our problem is `solved' by turning the engine off and back on again. ie rebooting the high speed bus. There are about 5 modules networked onto this high speed bus, and the problem could be in any one of them apparently.
Befire that on an older Ford I have had a problem with the voltage regulator chip that feeds the Instruments. If it gets too hot it will safeguard itself - and shut down. When it cools it will turn back on again ...
Other than that do you have relay with burnt contacts ? I have had a partially bad relay which had me running around in circles, because sometimes the contacts closed properly, sometimes not.
Not sure if any of this is relevant to you though !
The main body ground is a mesh strap that runs from a tranny bellhousing bolt to the body usually on GM's.
A secondary one runs from the battery negative to the body by the battery. A symptom of the main ground dead will be the small one by the battery first melting the insulation, then cooking.
I also think the frame has a ground strap across an engine mount, but am not sure where.
The vehicle can 'steal' some ground and run sometimes, but....
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