Hi guys- when sitting at idle,sometimes my speedo will jump around- also when im in drive sometimes my oil press gauge will do almost full sweeps - most likely electrical-has any one had this particular problem and any info on it----Thanks
CK5
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fluctuating gauges...90 sub-350
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bp71k5
3/4 ton status
If the speedo is run on a cable, the cable needs to be lubricated.
I have a aftermarket full electric speedo that does a full sweep once in a while, but it seems related to a voltage drop or spike.
I have a aftermarket full electric speedo that does a full sweep once in a while, but it seems related to a voltage drop or spike.
First thing I'd do is check your ground strap from the left rear head to the body, loose broken or missing.
Just those two instruments? Odd that the speedometer will move around, even if there was voltage fluctuation since it's signal comes from elsewhere, and voltage fluctuates a fair bit under "normal" conditions anyway.
Oil pressure I'd almost lean towards the sender or wiring to it. When the cluster starts to have issues (the connector is garbage) normally all the gauges go goofy. You could test the oil pressure wire for continuity to ground, or a break, with a multimeter.
Thanks-can you tell me where the guage cluster connector is at, the very back of the cluster or somewhere on the harness? Ps, yeah only those 2 giving me trouble + im not any good with the multimeters[ I should probably start to learn]
Yes, multimeter will make your life MUCH easier as you get more into electrical. Super simple for the most part.
Cluster connector is indeed on the back of the cluster. It's a plug that locks into the back of the cluster, and it pinches the flexible circuits contacts between it and the contacts in the plug. Those do tend to screw up. But normally they screw up the entire cluster.
Additionally, with this being a '90, the cluster circuit is a lot more dependent on common grounds and 12V....I believe the oil pressure, volt gauge, and engine temp (among others) all share the same 12V and ground...thus if it was a ground or 12V issue, all would have issues. That doesn't mean the problem can't be the connector at the back of the gauge or at the cluster plug, but I'd be making darn sure the sending units/wiring to the cluster were good before tearing into the cluster.
Cluster connector is indeed on the back of the cluster. It's a plug that locks into the back of the cluster, and it pinches the flexible circuits contacts between it and the contacts in the plug. Those do tend to screw up. But normally they screw up the entire cluster.
Additionally, with this being a '90, the cluster circuit is a lot more dependent on common grounds and 12V....I believe the oil pressure, volt gauge, and engine temp (among others) all share the same 12V and ground...thus if it was a ground or 12V issue, all would have issues. That doesn't mean the problem can't be the connector at the back of the gauge or at the cluster plug, but I'd be making darn sure the sending units/wiring to the cluster were good before tearing into the cluster.
Thank you ----ill be checking some wiring diagrams for my grounds and the engine sending units....
