Gauge issues

[CA_LEO]

Hey all, new to the forum but I have been lurking about for a while.

So the other day, I went to start my 86 M1009 up. The glow plug light, water in fuel light, Gen 2 light, and volt gauge stopped working. I opened up the dash and looked everywhere for a loose/broken wire/ground but was unable to find anything. Fuses all checked out too. Any help would be very much appreciated.

 

[Warthog]

If you have a volt meter check the very bottom fuse. Pull the fuse and see if you have 24v on the left side. If not the fusable link coming off the 24v terminal block may be blown.

I don't have the curcuit diagram in front of me but this fusable link feed the bottom fuse which in turn feeds the volt meter, gen2 light and thru the Gen2 relay supplies power to the wait and water lights.

If you do have power on the left terminal, reinstall the fuse and make sure you have 24v on the right side. Since you have the dash out you can check to see if the 24v is being supplied to the volt meter on the "fat" side of the plug.

I can post some pictures tomorrow when I get to work.

Warthog

 

[CA_LEO]

Thanks, I would appreciate those picks.

 

[Warthog]

From the TM 9-2320-289-34 Appendix E.

The fusible link is on the 24v positive terminal block behind the back battery. I will take a picture of it and post it

Right click the picture and choose "Open Link in New Window"

 

[CA_LEO]

Thank you so much Sir! I owe you big time.

 

[Warthog]

Call me slow......After looking over the wiring diagrams I think I was leading you in the wrong direction.

Stiil check the bottom fuse for voltage but also check the fuse and fuse holder of fuse #15 - 20 Amp Ignition Fuse. Make sure the contacts are clean. Recheck them all for that matter.

Looking at the E-4 diagram the #15 fuse feeds the following circuits:

Volt Meter relay
Gen2 Relay
Transmission Downshift
Water in Fuel lamp
Low Coolant Module
and the Wait Light

All the syptoms you described.

The wife took the camera so I didn't get any pics of the fusable link.

Warthog

 

[CA_LEO]

Warthog, thank you so much Sir. It was the #15 and the #12 fuses. They both looked alright and checked out fine with my fuse tester, but I changed the #15 fuse and the voltage gauge came to life. Looked at the schematic for the fuses and tried changing the #12 fuse, everything else came on.

Now I am wondering what caused both of them to trip out of nowhere.

 

[4bogginchevys]

corrosion

 

[1956_4x4]

Warthog, thank you so much Sir. It was the #15 and the #12 fuses. They both looked alright and checked out fine with my fuse tester, but I changed the #15 fuse and the voltage gauge came to life. Looked at the schematic for the fuses and tried changing the #12 fuse, everything else came on.

Now I am wondering what caused both of them to trip out of nowhere.

Check the connection where the fuse plugs into the fuse block. I've had problems in this area on these trucks.

Smitty

 

[Warthog]

Warthog, thank you so much Sir. It was the #15 and the #12 fuses. They both looked alright and checked out fine with my fuse tester, but I changed the #15 fuse and the voltage gauge came to life. Looked at the schematic for the fuses and tried changing the #12 fuse, everything else came on.

Now I am wondering what caused both of them to trip out of nowhere.

Glad I could help. These trucks saw some rough service and with the dirt, grime and moisture, the fuse boxes saw alot of abuse.

It is a good idea to remove all the fuses and clean each and every contact (disconnect the batteries first). Remember they are over 25 years old and where not designed to be water/dust/dirt proof.

 

[a68cudas]

Hey all, new to the forum but I have been lurking about for a while.

So the other day, I went to start my 86 M1009 up. The glow plug light, water in fuel light, Gen 2 light, and volt gauge stopped working. I opened up the dash and looked everywhere for a loose/broken wire/ground but was unable to find anything. Fuses all checked out too. Any help would be very much appreciated.

Same thing happened to me but blazer still started. when i checked fuse that runs all the above it looked ok but i replaced it and everything started working again. the # 15 fuse was my problem it looked good but wasnt. I took all my fuses out un hook both batteries so no power going anywhere got elec circuit cleaner and sprayed all connectors and replaced all fuses with new.