The warning light circuit is not a straight connection like the indicator, so you might get tripped up with a multimeter since there are diodes in the circuit. I'd just use the 9v battery on b4 and a13 as shown in that post. There's a slight chance 9 volts isn't enough in that circuit, so if the light does not go on that way, it would be best to test with 12 volts before declaring the cluster bad. If so, report back and we'll come up with a (safe) MacGyver 12 volt source.
Re: instrument cluster warning lights
Posted: Wed Jun 03, 2026 2:56 am
by blade7
You don't get this level of tech advice on other 944 forums
Re: instrument cluster warning lights
Posted: Fri Jun 05, 2026 12:01 am
by facboy
@Tom don’t suppose you have that write up for testing the boost gauge?
Re: instrument cluster warning lights
Posted: Fri Jun 05, 2026 2:47 am
by blade7
facboy wrote: Fri Jun 05, 2026 12:01 am
@Tom don’t suppose you have that write up for testing the boost gauge?
I wouldn't rely on the standard boost being very accurate, I always run an external gauge.
Re: instrument cluster warning lights
Posted: Fri Jun 05, 2026 4:17 am
by blade7
Tom wrote: Tue Jun 02, 2026 5:08 pm
Here's a video showing how to use a multimeter to test the indicator circuit on the cluster. I made it fairly generic for a wider youtube audience, but if you watch to the end I also show how to test the indicator light with just a 9 volt battery. If your cluster passes these tests (multimeter or 9 volt battery) with a regular light bulb, the the cluster isn't your issue.
p.s., if you don't have a 9 volt battery clip, you can just have a helper hold wires to the battery terminals for testing....
There's good news, and maybe not good news. There is continuity to the flasher warning light in the cluster, but the warning bulb flashed a few times and then all the external flashers and the hazard switch stopped flashing, and just stayed on. Which is odd because all the external flashers and the hazards had been working fine before. I did have to fiddle with the LEDs to make sure their wires were making contact inside the holders, and now the big red warning light is working too. So is it likely a flasher relay issue, or has the LED caused an issue? I guess I could buy a new standard bulb and substitute that.
Tom wrote: Tue Jun 02, 2026 5:08 pm
Here's a video showing how to use a multimeter to test the indicator circuit on the cluster. I made it fairly generic for a wider youtube audience, but if you watch to the end I also show how to test the indicator light with just a 9 volt battery. If your cluster passes these tests (multimeter or 9 volt battery) with a regular light bulb, the the cluster isn't your issue.
p.s., if you don't have a 9 volt battery clip, you can just have a helper hold wires to the battery terminals for testing....
There's good news, and maybe not good news. There is continuity to the flasher warning light in the cluster, but the warning bulb flashed a few times and then all the external flashers and the hazard switch stopped flashing, and just stayed on. Which is odd because all the external flashers and the hazards had been working fine before. I did have to fiddle with the LEDs to make sure their wires were making contact inside the holders, and now the big red warning light is working too. So is it likely a flasher relay issue, or has the LED caused an issue? I guess I could buy a new standard bulb and substitute that.
Not sure if it's relevant, but a new 9v battery got quite hot when I was testing the LED bulbs.
Tom wrote: Tue Jun 02, 2026 5:08 pm
Here's a video showing how to use a multimeter to test the indicator circuit on the cluster. I made it fairly generic for a wider youtube audience, but if you watch to the end I also show how to test the indicator light with just a 9 volt battery. If your cluster passes these tests (multimeter or 9 volt battery) with a regular light bulb, the the cluster isn't your issue.
p.s., if you don't have a 9 volt battery clip, you can just have a helper hold wires to the battery terminals for testing....
There's good news, and maybe not good news. There is continuity to the flasher warning light in the cluster, but the warning bulb flashed a few times and then all the external flashers and the hazard switch stopped flashing, and just stayed on. Which is odd because all the external flashers and the hazards had been working fine before. I did have to fiddle with the LEDs to make sure their wires were making contact inside the holders, and now the big red warning light is working too. So is it likely a flasher relay issue, or has the LED caused an issue? I guess I could buy a new standard bulb and substitute that.
Not sure if it's relevant, but a new 9v battery got quite hot when I was testing the LED bulbs.
Oops, that test was intended for regular light bulbs only! Most LED's require a current limiting resistor or they will draw too much power. The reduced voltage (9 vs 12+) may have saved you -- it's quite easy to blow up an LED that way. They can even snap like little fire crackers...
Edit: on the other hand, if the LED did light up when you put 9v battery power to b6 and b7, it means your cluster is fine as far as the indicator light is concerned. (I'd just limit it to quick blinks of the LED rather than leaving it powered on for any length of time.) Just be sure the LED lights up when the positive battery lead is on b7 and negative on b6. If it lights up only when those are reversed, it means the LED is installed backwards and therefore won't work when the cluster is installed.
