Gauge Cluster Issues, Where to start? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

D-n-Tyke · 07-28-2023, 03:39 PM

So final got the truck up and running and am now trying to figure out this gauge cluster. Have the temp gauge, fuel gauge and the amp gauge hooked up. Speedo and oil pressure are not connected so of course those are not worrying at this moment.
The 3 hooked up gauges, temp, amp and fuel, all seem to be working, along with the both green arrows for the directionals. The problem I am having is when either of the directionals are turned on, the gauges go crazy. The temp gauge sweeps to pegged and then back to normal at the beat of the flasher. The fuel gauge stops working and slowly goes to empty. As soon as the directional is canceled things go back to normal. Additionally, when I turn the headlights on I loose all the gauges. I thought it might be a bad ground but I checked the ground where it attaches to the back of the metal dash and where the wire goes into the harness connector and have solid ground at both locations.

I am not sure where to go from here. What to check next. Has someone else had this similar issue and what was the solution that fixed it.

**Steeveedee** · 07-28-2023, 03:42 PM

Is the panel grounded properly?

**pjmoreland** · 07-28-2023, 05:00 PM

Like Steeveedee asked, is your metal dashboard grounded properly? Do you have grounding straps installed between your firewall and engine?

body bolt · 07-28-2023, 05:00 PM

...and is that connector plugged in the correctly?

michael bustamante · 07-28-2023, 05:18 PM

are you using oem guages or aftermarket?

D-n-Tyke · 07-28-2023, 11:40 PM

Okay, I will try and answer all these questions.

Metal dash is grounded. This was testes using my power probe to verify there was ground there all the way back to the battery. Clip on the dash shows solid ground. Ground wire into the connector shows ground back to the battery.

Don't currently do not have a ground strap from the engine to the firwall. I will add one and see if that changes anything. However, as said above, my probe shows there is solid ground from the metal dash to the battery, so I am going to assume that the engine to firewall isn't going to fix this.

Gauges are the OEM gauge cluster.

Best I can tell connector is pligged in correctly and fully seated.

**dmjlambert** · 07-29-2023, 12:00 AM

Was the truck made for a warning light instrument cluster, and now you're putting a gauge cluster in it? If so, the plug is pinned wrong.

D-n-Tyke · 07-29-2023, 12:16 AM

Ground strap added from block to firewall. No change in issues.

**too much stuff** · 07-29-2023, 08:20 AM

Quote:

Originally Posted by dmjlambert

Was the truck made for a warning light instrument cluster, and now you're putting a gauge cluster in it? If so, the plug is pinned wrong.

Check this...

D-n-Tyke · 07-29-2023, 12:13 PM

Quote:

Originally Posted by too much stuff

Check this...

As far as I know the cluster is the original cluster. It was there when i bought the truck and looks to have never been removed.

D-n-Tyke · 07-29-2023, 12:21 PM

Reviewing the full wiring diagram post on here, the connector is pinned out as shown for the cluster with gauges.

**dmjlambert** · 07-29-2023, 03:00 PM

OK, good. Next is do the buckets for the front parking lights/turn signals have a good ground? Do you have any LED bulbs installed in the truck such as in the front marker lights or front parking lights/turn signals?

D-n-Tyke · 07-29-2023, 06:44 PM

Quote:

Originally Posted by dmjlambert

OK, good. Next is do the buckets for the front parking lights/turn signals have a good ground? Do you have any LED bulbs installed in the truck such as in the front marker lights or front parking lights/turn signals?

Are you talking buckets in the turn signals themselves (ie in the front grille (1969 truck) or the buckets in the cluster?

There are no LED bulbs in anything. All OG filiment style bulbs.

**dmjlambert** · 07-29-2023, 07:10 PM

Yes, buckets in the turn signals in the front grille need to be grounded. If not, you'll get wacky goings on. I don't know for sure about the specific wacky things you have going on, but some wackiness nevertheless.

**dmjlambert** · 07-29-2023, 07:14 PM

Did you paint the metal parts of your instrument cluster? 2 of the screws that go through the printed circuit need to be good grounding points for the printed circuit traces.

D-n-Tyke · 07-29-2023, 07:41 PM

Quote:

Originally Posted by dmjlambert

Did you paint the metal parts of your instrument cluster? 2 of the screws that go through the printed circuit need to be good grounding points for the printed circuit traces.

Gauge cluster is original patina. Hasn't been painted.

**pjmoreland** · 07-29-2023, 07:56 PM

Do you have the two screws installed in the upper back of the gauge cluster that ground the flexible circuit board to the metal case of the cluster?

07-28-2023, 03:39 PM	#1
D-n-Tyke Registered User Join Date: Aug 2016 Location: El Cajon, CA Posts: 256	Gauge Cluster Issues, Where to start? So final got the truck up and running and am now trying to figure out this gauge cluster. Have the temp gauge, fuel gauge and the amp gauge hooked up. Speedo and oil pressure are not connected so of course those are not worrying at this moment. The 3 hooked up gauges, temp, amp and fuel, all seem to be working, along with the both green arrows for the directionals. The problem I am having is when either of the directionals are turned on, the gauges go crazy. The temp gauge sweeps to pegged and then back to normal at the beat of the flasher. The fuel gauge stops working and slowly goes to empty. As soon as the directional is canceled things go back to normal. Additionally, when I turn the headlights on I loose all the gauges. I thought it might be a bad ground but I checked the ground where it attaches to the back of the metal dash and where the wire goes into the harness connector and have solid ground at both locations. I am not sure where to go from here. What to check next. Has someone else had this similar issue and what was the solution that fixed it.

07-28-2023, 03:42 PM	#2
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,234	Re: Gauge Cluster Issues, Where to start? Is the panel grounded properly? __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

07-28-2023, 05:00 PM	#3
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,363	Re: Gauge Cluster Issues, Where to start? Like Steeveedee asked, is your metal dashboard grounded properly? Do you have grounding straps installed between your firewall and engine?

07-28-2023, 05:00 PM	#4
body bolt Registered User Join Date: Oct 2020 Location: Albuquerque, New Mexico Posts: 475	Re: Gauge Cluster Issues, Where to start? ...and is that connector plugged in the correctly?

07-28-2023, 05:18 PM	#5
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,841	Re: Gauge Cluster Issues, Where to start? are you using oem guages or aftermarket? __________________ 1967custom

07-28-2023, 11:40 PM	#6
D-n-Tyke Registered User Join Date: Aug 2016 Location: El Cajon, CA Posts: 256	Re: Gauge Cluster Issues, Where to start? Okay, I will try and answer all these questions. Metal dash is grounded. This was testes using my power probe to verify there was ground there all the way back to the battery. Clip on the dash shows solid ground. Ground wire into the connector shows ground back to the battery. Don't currently do not have a ground strap from the engine to the firwall. I will add one and see if that changes anything. However, as said above, my probe shows there is solid ground from the metal dash to the battery, so I am going to assume that the engine to firewall isn't going to fix this. Gauges are the OEM gauge cluster. Best I can tell connector is pligged in correctly and fully seated.

07-29-2023, 12:00 AM	#7
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,619	Re: Gauge Cluster Issues, Where to start? Was the truck made for a warning light instrument cluster, and now you're putting a gauge cluster in it? If so, the plug is pinned wrong.

07-29-2023, 12:16 AM	#8
D-n-Tyke Registered User Join Date: Aug 2016 Location: El Cajon, CA Posts: 256	Re: Gauge Cluster Issues, Where to start? Ground strap added from block to firewall. No change in issues.

07-29-2023, 12:21 PM	#11
D-n-Tyke Registered User Join Date: Aug 2016 Location: El Cajon, CA Posts: 256	Re: Gauge Cluster Issues, Where to start? Reviewing the full wiring diagram post on here, the connector is pinned out as shown for the cluster with gauges.

07-29-2023, 03:00 PM	#12
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,619	Re: Gauge Cluster Issues, Where to start? OK, good. Next is do the buckets for the front parking lights/turn signals have a good ground? Do you have any LED bulbs installed in the truck such as in the front marker lights or front parking lights/turn signals?

07-29-2023, 07:10 PM	#14
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,619	Re: Gauge Cluster Issues, Where to start? Yes, buckets in the turn signals in the front grille need to be grounded. If not, you'll get wacky goings on. I don't know for sure about the specific wacky things you have going on, but some wackiness nevertheless.

07-29-2023, 07:14 PM	#15
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,619	Re: Gauge Cluster Issues, Where to start? Did you paint the metal parts of your instrument cluster? 2 of the screws that go through the printed circuit need to be good grounding points for the printed circuit traces.

07-29-2023, 07:56 PM	#17
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,363	Re: Gauge Cluster Issues, Where to start? Do you have the two screws installed in the upper back of the gauge cluster that ground the flexible circuit board to the metal case of the cluster?



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