S-10 Forum banner
1 - 20 of 35 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi, I'm new to the site and have a 94 S-10 2wd 4.3 5 speed. I have been having intermittent issues with the instrument cluster. When I turn the headlights on, and the dash lights up, it shorts in and out, sometimes staying lit up but blacking out, flickering on and off. The gauges are also affected by this...for example, the gas gauge, oil pressure gauge, etc all start to go crazy. When I unplug the dimmer switch by the headlight switch, all the shorts seem to go away, and the gauges work as they should.

Also when I use the cruise control, it seems to work fine (the truck will hold its speed that i set it at), but while the cruise is on, the gauges go all crazy again.

Any ideas what the issue is? Could this be a bad instrument cluster? Or is it a bigger issue?

Thanks in advance.
 

·
Electrical Mod
Joined
·
56,116 Posts
sounds like you have a short or a bad ground somewhere. Check my wiring diagrams in my sig and see if you find any common grounds or places where wiring is similiar.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #3 ·
Thanks, I'll check those out. I'm hoping its just the cluster that's bad so I can find a junkyard one and throw it in there.
 

·
Electrical Mod
Joined
·
56,116 Posts
you realize that the cluster is 94 specific. Meaning unless you know of a junkyard with a 94 in it, it's next to impossible to find. It took me a year to find a cluster with a tach for a reasonable price. It doesn't sound like a cluster issue, the only times the cluster messes up is because of an outside variable.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #5 ·
My current cluster does not have a tach....it would be great to have one, but I might just hook up an aftermarket tach...might be easier.

So would I not be able to use any other year cluster than a 94? And would it have to be a cluster out of a 94 s10 that was a 5 speed?
 

·
Electrical Mod
Joined
·
56,116 Posts
Only 94 clusters will work, because 95 clusters are a different shape (new steering column) and use a different connector, it's 2 pins bigger.

You will need any cluster from a manual transmission, the one's from auto's will work, but they have the extra PRNDL you won't need. And if it has a tach, it will need to be from a v6 truck, although you can recalibrate a tachometer from a 4 cylinder truck. If it does not come with a tach, then the engine won't change anything. You can also change the mileage to reflect your current mileage as well.
 

·
Registered
Joined
·
190 Posts
hey my gas gauge wont work, and somone told me this could be the problem, its also a 94 v6 4.3, with a tach, i have already had all my gas tank sending unnit everything replace and still nothing somone said that this could be it its it true?
 

·
Registered
Joined
·
190 Posts
yes it moves when i turn it on and off, when its off it goes up to about right above the red and once i turn it on it just goes empty
 

·
Electrical Mod
Joined
·
56,116 Posts
sounds like you have a short, the way way it works, if if the gas gauge sees 0 ohms of resistance, it's on empty, and at 90 ohms I believe is full. So if you didn't have a ground, then it'd show past full, but since you say its on empty, then I think you may have a short to ground somewhere. You will probably have to trace the wiring. Or pull the cluster out and test the correct pin, see what the resistance is, that'll tell you if it's a problem with the wiring or the cluster.
 

·
Electrical Mod
Joined
·
56,116 Posts
I'm not sure what you mean, bending pins in the tank? No, if the fuel sender was bad, it'd be at full all the time when on. Unless your float sinks and is at the bottom of the gas, then it shounds like a short to ground somewhere.
 

·
Electrical Mod
Joined
·
56,116 Posts
alright, it's not about bending pins, it's common that when you remove the cluster and put it back in, you don't properly seat the connector as it's a laminated circuit board. SO unless you've removed it recently, I don't think that'd be the problem.
 

·
Electrical Mod
Joined
·
56,116 Posts
Gauge Stays At EMPTY
Disconnect fuel tank sending unit connector. Turn ignition on. If gauge indicates FULL, replace sending unit. If gauge indicates EMPTY,
check Purple (Pink on some models) wire between sending unit and cluster. If wire is okay, replace instrument cluster.
Gauge Stays At FULL
1. Disconnect fuel tank sending unit connector. Turn ignition on. Connect fused jumper wire between ground and Purple (Pink on some
models) wire terminal of sending unit connector. If gauge indicates EMPTY, go to next step. If gauge indicates FULL, check Purple
(Pink on some models) wire between sending unit and cluster (terminal No. A12). If wire is okay, replace instrument cluster.
2. Connect fused jumper wire between sending unit ground and Purple (Pink on some models) wire terminal of sending unit connector.
If gauge indicates EMPTY, replace sending unit. If gauge still indicates FULL, repair sending unit ground.
Gauge Is Inaccurate
1. Disconnect fuel tank sending unit connector. Connect Red lead of Instrument Panel Tester (J-33431) to Purple (Pink on some
models) wire terminal of sending unit connector, and connect other lead to ground. Turn ignition on.
2. Set tester dial to zero ohms, then 90 ohms. If fuel gauge indicates EMPTY at zero ohms and FULL at 90 ohms, check sending unit
ground. If ground is okay, replace sending unit. If fuel gauge does not indicate as specified, check Purple (Pink on some models)
wire between sending unit and cluster. If wire is okay, replace instrument cluster.


Another thing as I stated, is to take the cluster out and measure the correct pin. Set one probe on the pin and the other on a known good ground. Read the resistance.

Pin S, should be a purple wire, appears to be the only purple wire.
 
1 - 20 of 35 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top