Ford 1920, Wiring Issues

[Jchawk]

Good afternoon! I have a 1989 Ford 1920, FEL, 17xx hours.
The coolant level light and temperature gauge are having issues.
Coolant Level Light - stays on (flickering slightly).
Temperature Gauge, remains at 'cold' through startup and working for a few hours in 65deg weather.

Following advice in similar threads, I've tried:
1. Unplugged coolant level sensor, light remained on (flickering slightly).
2. Unplugged coolant temperature sensor, gauge did not change.
3. Grounding coolant temperature lead, gauge did not change.
4. Validated thermostat function, when cold no/very little flow of coolant. When hot, coolant flows correctly.

What could cause similar issues with both? Could a bad ground cause an issue across both?

Thank you for your time!

 

[Sprinklerman]

yes a bad ground could

 

[Jchawk]

Anyone know where the ground for the dash harness is? It is not the dash itself

 

[Sprinklerman]

Sometimes you have to run a new one .

 

[kirkawilson]

I hope my previously uploaded 1920 wiring diagram properly attached.

 

[MIkeWard]

I have the same problem with the coolant level light.
I read somewhere on this site that Ford discontinued this warning light because of the light not working correctly

My light goes on sometimes when the coolant recovery container is full. I took a long screwdriver and carefully stirred up the bottom of the coolant container and tapped the plunger at the bottom a few times. The light went out and everything worked correctly for months till I had to do it again

Mike

 

[Jchawk]

Hi Mike! Thank you for your response. I actually unplugged the sensor and the light stayed on. I think I have either a short or some other issue since both temp gauge and coolant overflow tank light are not working. I will open it up and try running to ground direclty off guage. If that doesn't work - no idea.

 

[Jchawk]

Kirk, unfortunately the attachment is not working. Can you try PM to me?
I have the owners manual and service manual but neither have proper wiring diagram.
Thanks!