Another BX25D with a dead dash

Wiz

New member
Jun 9, 2018
12
2
3
Dover, NH
My 2200 hour BX25D has a dead dash. It was parked outside but under a cover. I removed the dash and cleaned the contacts. I only found corrosion in the Tach motor. I cleaned it and then reconnected without the housing. I used a meter to check some of the contacts. 12V + and ground is working and I'm getting voltage on others. The only thing working is the left & right turn signal lights.
 

jaxs

Well-known member

Equipment
B1750HST
Jun 22, 2023
733
522
93
Texas
"Cleaned the contacts"?????? How did you clean them? Put a load ( something like a non-led tail light with clips on leads) on each circuit and see if voltage remains unchanged. By unchanged I mean no change in tenths of volt. Keep in mind that like a chain being only strong as it's weakest link, a circuit is only as good as the worst connection in the entire circuit. I reccomend applying spray cleaner to all contact points including fuses,plugs and switches as you are inspecting. The best cleaners and protectants I've found is the Deoxit line of products.
Let me know how the test goes while having a load and we can go the right direction.
 

Wiz

New member
Jun 9, 2018
12
2
3
Dover, NH
"Cleaned the contacts"?????? How did you clean them? Put a load ( something like a non-led tail light with clips on leads) on each circuit and see if voltage remains unchanged. By unchanged I mean no change in tenths of volt. Keep in mind that like a chain being only strong as it's weakest link, a circuit is only as good as the worst connection in the entire circuit. I reccomend applying spray cleaner to all contact points including fuses,plugs and switches as you are inspecting. The best cleaners and protectants I've found is the Deoxit line of products.
Let me know how the test goes while having a load and we can go the right direction.
I cleaned with some worn out sand paper. I got some steel wool to try today. The holes in the multiplug were too small to insert my tester leads so I inserted the plug in the connecter on the back of the dash circuit board. I left off the housing. I put negative on negative and tried some of the others leads.
 

Wiz

New member
Jun 9, 2018
12
2
3
Dover, NH
I just realized what you were asking. I cleaned the pins. I also opened up the tach motor and cleaned the rust out of it.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,781
2,965
113
North of Pittsburgh PA
My 2200 hour BX25D has a dead dash. It was parked outside but under a cover. I removed the dash and cleaned the contacts. I only found corrosion in the Tach motor. I cleaned it and then reconnected without the housing. I used a meter to check some of the contacts. 12V + and ground is working and I'm getting voltage on others. The only thing working is the left & right turn signal lights.
I am not sure what this means, but I would make all my voltage measurements with respect to the negative battery post, since the battery posts are as close to the source of the 12 volts from the battery as you can get...I assume that you can still turn the engine over when you put the key in the start position?

The more details you share the more likely someone here will be able to give some great guidance...
 

Wiz

New member
Jun 9, 2018
12
2
3
Dover, NH
I am not sure what this means, but I would make all my voltage measurements with respect to the negative battery post, since the battery posts are as close to the source of the 12 volts from the battery as you can get...I assume that you can still turn the engine over when you put the key in the start position?

The more details you share the more likely someone here will be able to give some great guidance...
Hi what I mean is, using my meter, I put negative on pin 16 (ground), and tested the various other pins.
Pin 2 (battery) and got 12v.
Pin 4 tachometer voltage seem to vary slightly increasing with engine speed. I should have made notes for each one. I did this by plugging the dash panel into the purple multi-connector which left some of each pin exposed. I did it with it plugged in because I was afraid to push my meter test leads into the connector as they look pretty small and I didn't want to stretch them out.
 

jaxs

Well-known member

Equipment
B1750HST
Jun 22, 2023
733
522
93
Texas
You dove in way too deep before looking at the simple things first. I'm glad you want to troubleshoot your problems rather than taking them to the dealer and we're here to help for as long as you want. Step #1 when there's electrical malfunction , test post to post on battery. 12.6 or higher is full charge, 12 even is only 50% charged and will do ok for testing circuits but you also need to find out why it's not 12.6+ and fix it (from here on this will be called "post voltage). Step #2 after finding 12.6+ . Move leads to cable connectors. ANY LESS THAN POST voltage screams dirty cable connections. Step #3 after finding post voltage at cable connectors, put + probe on + post then - probe on chassis of vehicle. Any less than post volts indicates poor contact between - cable and chassis. As Henro suggested put - probe on - post then proceede to use + probe for testing connections for post volts as they move farther from battery. If and when leads are too short to keep - probe on - post, clean a spot on chassis and connect - probe there. If volts drop 0.1 at any point you have found poor contact/conection,fix it then move on. When you reach a plug , relay or stwith,test it as you have been and I recommend giving it a shot of spray cleaner/lub to prevent future corrosion. Same applies to to cable connections after they are sanded. That covers + connections ,put + probe on + post then test - wires and connections.
Master the above and here's a few tips to speed the process. If a piticular device fails you can usually test switches , relays and connections by turning device on or hooking a load such as tail lamp/head lamp then touching a probe to in and other probe to out. Volt reading eaual or near post volts indicates bad connection,relay or switch. Aligator clamps for meter probes will free up the hand otherwise required for holding a probe. Short pieces of bare copper wire ranging from 16 gauge to 14 guage can be pushed into plugs where meter probe is too large.
I hope you find something you can use in that.
 
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