Electric Malfunctions
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From: Small acerage in Nebraska
Electric Malfunctions
Thought i'd post this thread and see if anyone has a soultion or suggestions.
I have a 91 bronco with a 90 dash,wires and all from a parts bronco I scrapped several years ago, never had it running. Now I have no dash lights, yes I checked the fuses. Also oil pressure and temperature are not reading, needle stays pegged left. No error codes for ect, no engine light for oil pressure being low. I suspect a bad ground under the dash,but not sure where to find it.
I have a 91 bronco with a 90 dash,wires and all from a parts bronco I scrapped several years ago, never had it running. Now I have no dash lights, yes I checked the fuses. Also oil pressure and temperature are not reading, needle stays pegged left. No error codes for ect, no engine light for oil pressure being low. I suspect a bad ground under the dash,but not sure where to find it.
Lead Driver
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From: Gateway to the West
Ok, first, the ECT sensor does not feed the gauge. The temp gauge uses a separate sending unit in the block.
If the needles on both gauges refuse to come off there "off" positions AND you have no dashboard lights, I'd be searching for a loose ground (negative) coming from the dash to the frame. If I am remembering correctly the negative for those circuits comes down to the firewall near the parking brake pedal assembly. However, trusting my memory alone would be like following a 40 y/o map. Still, my first thought would be a loose or broken negative that most likely feeds all of those things.
If the needles on both gauges refuse to come off there "off" positions AND you have no dashboard lights, I'd be searching for a loose ground (negative) coming from the dash to the frame. If I am remembering correctly the negative for those circuits comes down to the firewall near the parking brake pedal assembly. However, trusting my memory alone would be like following a 40 y/o map. Still, my first thought would be a loose or broken negative that most likely feeds all of those things.
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After reinstalling my gauge cluster I lost oil pressure.. I get power with key in ON position, but hit the ignition and it pegs left. I guess it just didn't like being unplugged and plugged back in.
Check the cord going into the cluster, I know in my 78 it would get sorta screwy and I had to make sure it was pressed in further, even after it clicked, I suspect that's what's going on with mine.
Check the cord going into the cluster, I know in my 78 it would get sorta screwy and I had to make sure it was pressed in further, even after it clicked, I suspect that's what's going on with mine.
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From: Small acerage in Nebraska
And how is that not possible? Everything plugs in to color coded different shape connections, Ground wires are all connected to a clean ground,and verified with a continuity test.
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From: Small acerage in Nebraska
not sure which cluster I used but have spares I could swap in to try. Have all the warning lamps including high beam indicator, no back lighting.
Is there a websight with a wiring diagram for dash? Could use one for the radio circuit as well, I hate to run extra wires when they are already at the opening.
Is there a websight with a wiring diagram for dash? Could use one for the radio circuit as well, I hate to run extra wires when they are already at the opening.
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Helminc.com has the diagrams, 1989 Bronco/F 150-350 Electrical & Vacuum Troubleshooting Manual - Helm Incorporated
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From: Small acerage in Nebraska
This is starting to get frustrating!!! I am hoping that the backlighting will be fixed with a new switch, at least thats where the power stops showing. Oil pressure and engine temp are making me pull my hair out!!!! Changed the dash cluster with one I knew to be working fine, same issue. Elimanated the sensors as the problem by changing the sensors, not it. chcecked the wiring to the connector on the fender, no shorts or open connections. I need to check the wiring from fender to dashboard. (Oil pressure is 60psi at idle) I don't have the $ to buy the Helm book yet. My Haynes and Chiltons manuals are not much help from here on.
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From: Small acerage in Nebraska
Finally got time to work on bronco again, was turning on dome light and saw a spark where the shaft goes into the dash,lost my tail lights, just before I went past a city cop. Gave me a fix-it. Replaced light switch. Found old one to have been damaged, big crack down the side of it.
backlighting is working fine now. Waiting for a cuz to bring his service manual to figure out the oil and temp prob. 2 b cont...
backlighting is working fine now. Waiting for a cuz to bring his service manual to figure out the oil and temp prob. 2 b cont...
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From: Small acerage in Nebraska
I will have to say you were right gk, Traced every wire from the engine harness and then checked at the ECM connection. /ended up moving several wires from one connection to another. Double checked, tripple checked. Now oil pressure and temp gauges are working. Now engine runs rough at idle, and smells very rich. Waiting for more codes to pop up, cause something still isn't correct.
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