- Thread starter
- #81
Ordered it. Thanks for your help. I still have the replacement unit coming from cruiserparts but if I can fix this one too, I'll have a backup.
Let's all learn how to debug a GAUGE fuse blown due to a short circuit (1 Viewer)
- Thread starter vegas
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Yeah, that would work fine. Overpriced, but for a single order and free shipping...
cheers,
george.
cheers,
george.
- Thread starter
- #83
Of course it is way over priced. But I'm trading money for time. The electronics parts suppliers couldn't have it to me until late next week.
- Thread starter
- #84
I wish there was a way to get the Denso schematics and BOM so that we'd be able to repair all of these computers much easier.
- Thread starter
- #85
I do think the "27 620" markings on the TVS diode means 27V avalanche, 620W. Doing the math, this part would burn out if it had to shunt more than 24A at 27V. That's three times the capacity of the 7.5 Amp GAUGE fuse that protects the circuit. I wonder if that also means if the Amps stay under 7.5 would the part burn out at 85 Volts? I think so. 
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- www.george4wd.taskled.com
It'll avalanche at nominal 27V, it can't have 85V across it.... If it has 85V across it, then it has blown open circuit.
Part numbers on many parts are whatever the manufacturer decides on, so 27 620 'may be 27V 620W' or it could be just random digits pulled out of a bucket.
Just replace it and move on
Getting the BOM and schematics for most things is a dream, it'll happen around the same time that apple publishes that information for their products (an alternate definition of "when hell freezes over").
cheers,
george.
Part numbers on many parts are whatever the manufacturer decides on, so 27 620 'may be 27V 620W' or it could be just random digits pulled out of a bucket.
Just replace it and move on
Getting the BOM and schematics for most things is a dream, it'll happen around the same time that apple publishes that information for their products (an alternate definition of "when hell freezes over").
cheers,
george.
- Thread starter
- #87
That's the plan. Thanks for your help. It is too bad that we can't just have that information. What is it worth to anybody locked away somewhere?Just replace it and move on
Getting the BOM and schematics for most things is a dream, it'll happen around the same time that apple publishes that information for their products (an alternate definition of "when hell freezes over").
- Thread starter
- #88
The replacement TVS diode arrived today and I soldered it on. The short circuit observed before is gone. I plugged it into my truck and the GAUGE fuse didn't blow and now I have A/C again. I fixed the issue finally. Thank you @george_tlc for your help in identifying the part. It was the correct part and everything works perfect again! I can't believe how much work that was and that the repair worked.
G'day Champion!
Not sure how you managed to be so calm , well done and thanks for posting your saga - not that I understand that much of it.
Recently whilst driving I noticed the speedometer not working and about 30 minutes further on, I did smell mild burnt electrcals?
I have wasted a fair bit of time on this issue when the Gauge fuse blows every time I put the manual tranny 1995 1HZJ80R into reverse gear!
Unplugging the reverse switch connection on the gearbox seemed to solve it with all test guages showing, guages ie eng temp and speedometer working again.
Replaced the reverse switch on the gearbox but no joy - blown fuse again.
With ignition on, Fiddled with a test lamp in the fuse's slot which may have done more harm than good?
Ignition off and fuse out - Unplugged the reverse switch again, pulled both bulbs out and I have no buzz continuity from earth to the harness side reverse switch connector RB wire so that indicates no fault along to the rear? But ALSO the earth to above's yellow wire continuity BUZZED ???
Put bulbs back in and the continuity from earth to the harness side reverse switch connector RB wire is 0.00ohms and the continuity earth to it's yellow wire as above measured 8 ohms.
A continuity test from nearby body earth to both sides of the gauge fuse slot buzzes showing 18ohms on left and 6 on right.
Am a bit worried now as I'm preparing now for a boondocks journey using the 80.
As long as I keep the reverse gear switch disconnected, I can put the fuse back in and the dash lights, sub tank switch light and as all as above work.
But I am worried about not having the reverse lights working and the possibility of a serious meltdown somewhere.
Could you suggest anything to help please.
Cheers John.
Not sure how you managed to be so calm , well done and thanks for posting your saga - not that I understand that much of it.
Recently whilst driving I noticed the speedometer not working and about 30 minutes further on, I did smell mild burnt electrcals?
I have wasted a fair bit of time on this issue when the Gauge fuse blows every time I put the manual tranny 1995 1HZJ80R into reverse gear!
Unplugging the reverse switch connection on the gearbox seemed to solve it with all test guages showing, guages ie eng temp and speedometer working again.
Replaced the reverse switch on the gearbox but no joy - blown fuse again.
With ignition on, Fiddled with a test lamp in the fuse's slot which may have done more harm than good?
Ignition off and fuse out - Unplugged the reverse switch again, pulled both bulbs out and I have no buzz continuity from earth to the harness side reverse switch connector RB wire so that indicates no fault along to the rear? But ALSO the earth to above's yellow wire continuity BUZZED ???
Put bulbs back in and the continuity from earth to the harness side reverse switch connector RB wire is 0.00ohms and the continuity earth to it's yellow wire as above measured 8 ohms.
A continuity test from nearby body earth to both sides of the gauge fuse slot buzzes showing 18ohms on left and 6 on right.
Am a bit worried now as I'm preparing now for a boondocks journey using the 80.
As long as I keep the reverse gear switch disconnected, I can put the fuse back in and the dash lights, sub tank switch light and as all as above work.
But I am worried about not having the reverse lights working and the possibility of a serious meltdown somewhere.
Could you suggest anything to help please.
Cheers John.
Vegas, I’m new here on the forum and had this same issue just a few days ago. Gauge fuse blew on my 97 while driving in to work. I know enough to do some repairs but not enough to figure this all out so I appreciate your thread. My fuse blows when my AC is turned on so I’m guessing it’s one of the AC components shorting it out (air amplifier, ac pressure switch). Had an AC pressure switch replaced last year and it’s been working fine until now. I’m worried I’ll do more damage than good digging in to this. Do you know of any reliable places in Vegas I can have this repaired?
some journey ; great troubleshooting for us armchair electronic wannabes
