Author Topic: 1897 K10 - No hazards, but blinkers work  (Read 2083 times)

Offline lazyMlazyK

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1897 K10 - No hazards, but blinkers work
« on: September 08, 2022, 12:49:20 PM »
Hey guys, I've got a 1987 K10 that I'm working on getting the bugs out of recently.  The left and right blinkers work fine, but when I put the hazards switch on, nothing happens.  Could someone show me a diagram or a picture of where the relay is located for the hazards?  I have checked the fuse, and it's in fine shape - even ohmed it out to be certain.  I'm thinking the problem is either in the switch or in the relay.  I haven't had time to take apart the column yet to look at the switch, but would like to rule out the relay.

There's one round relay marked "224 12V WAGNER DOT on the fuse block - I believe that is for the blinkers?

There is also a small block with two relays on it under the radio area.  One of the relays is square/rectangular, and the other is round like the relay on the fuse block.  I've checked rockauto for hazard relays, and none of the relays offered there look like any I've seen so far under my dash.

Anyone here that could point me in the right direction?

Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #1 on: September 08, 2022, 01:45:41 PM »
The turn signal flasher plugs into the right lower corner of the fuse box.  The hazard flasher plugs into the "Convenience Center" located above the accelerator pedal on the interior firewall.  The three items that plug into the face of the Convenience Center are the seatbelt/ignition key/headlamp warning alarm module at the top, the horn relay at the lower left, and the hazard flasher at the lower right.  The hazard flasher and the turn signal flasher are interchangeable.  Swap the two flashers between the fuse box and the Convenience Center to see whether the problem follows the flasher.
« Last Edit: September 08, 2022, 01:57:25 PM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #2 on: September 12, 2022, 01:47:42 PM »
Thanks for the diagram and explanation!  I've replaced the flasher relay in the convenience center, but the hazards still aren't working.  It looks like there's a plug on the back of that relay with two wires coming off of it - an orange and a brown (maybe purple or gray?).  They then go into a loom that goes up toward the dash and out of sight.  Is there a way to troubleshoot the hazard switch off of these two wires? I think to get to the switch, I'll need to take the steering wheel of, which I'd rather not go through that process if I don't have to.

Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #3 on: September 12, 2022, 02:39:48 PM »
Use an incandescent test light clipped to a good bare metal ground and probe the two socket contacts for the hazard flasher.  The contact labeled 140 in the diagram posted previously should be constant B+.  Does it illuminate the test light?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #4 on: September 14, 2022, 11:17:15 AM »
Use an incandescent test light clipped to a good bare metal ground and probe the two socket contacts for the hazard flasher.  The contact labeled 140 in the diagram posted previously should be constant B+.  Does it illuminate the test light?
Using a 12v test light, neither one of the socket contacts would light it.

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Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #5 on: September 14, 2022, 03:03:08 PM »
Use your test light to probe both terminals of the STOP/HAZ fuse socket in the fusebox with the fuse installed.  Actually probe the fusebox terminals, not the blades of the fuse.  Do both terminals illuminate the test light?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #6 on: September 14, 2022, 04:28:37 PM »
Use your test light to probe both terminals of the STOP/HAZ fuse socket in the fusebox with the fuse installed.  Actually probe the fusebox terminals, not the blades of the fuse.  Do both terminals illuminate the test light?

I removed the fuse and tested the fusebox terminals.  One side of the STOP/HAZ fuse socket illuminated the probe, the other side did not.  This seems correct - I'm not sure why you ask if both terminals would illuminate the test light?  I may be misunderstanding something here.

I should note also - I can turn a side blinker on, watch the blinker indicator on the dash blink and hear the relay.  When I engage the hazard switch to turn the hazards on, the blinkers quit.  Disengaging the hazard switch lets the blinkers go back to doing their thing.  I've replaced the hazard relay, so I can probably rule out the relay not working.
« Last Edit: September 14, 2022, 05:13:35 PM by lazyMlazyK »

Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #7 on: September 14, 2022, 07:37:13 PM »
The problem you're experiencing is the lack of battery power reaching the hazard flasher.  The fusebox terminals have a propensity for losing electrical connection with the fuses as they age due to accumulated oxidation.  The challenge was to probe the fusebox contacts w/o removing the fuse to see whether continuity was lost through the fuse and its connections.  Reinstall the fuse and check for power as I originally proposed.  While the fuse is in your hand, inspect it closely for fine cracks severing the element (as opposed to being blown), which is another precedented potential issue.  If power is available at the load-side fuse terminal of the fusebox with the fuse installed then the orange wire (Ckt 140) between the fusebox and the Convenience Center is open.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #8 on: September 14, 2022, 08:10:32 PM »
Ah, I get it now.  Sorry for my confusion, work had me switch to a night shift this week (only do it for one week each year, this is my lucky week), so my brain's not firing on all cylinders.  I'll have to look at it a little more tomorrow if I get a chance. Thanks!

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #9 on: September 15, 2022, 11:18:45 AM »
Well, I had to bend one of the legs of the fuse to nearly 90* from its normal position, but I got the hazards working. Thanks for the information folks.

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Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #10 on: September 15, 2022, 11:44:13 AM »
What?   :o

That's not right!  Post a pic.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #11 on: September 16, 2022, 12:31:53 PM »
What?   :o

That's not right!  Post a pic.
Looks like I exaggerated, but it felt like 90 when I was pushing it in! Maybe 45.

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Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #12 on: September 16, 2022, 12:36:27 PM »
Here's a pic:

Offline bd

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #13 on: September 16, 2022, 01:53:29 PM »
Okay!  So, here's what you do.  First, throw that fuse in your pic away!   ;)

More than likely, the fusebox terminals are contaminated with dirt and/or oxidized.  If contamination is light, you can spray the blades of a new fuse with WD-40 and repeatedly insert and withdraw the fuse to burnish the fusebox terminals, which may be sufficient to restore continuity. 

If the fusebox terminals are grossly contaminated, you can scrub the terminals by smearing a light coat of fine-grit valve grinding compound on the blades of a sacrificial fuse and perform the same technique as described previously.  Then finish up with a thorough WD-40 rinse to wash away the abrasive. 

If the fusebox terminals are too distorted due to excessive heat from poor connection, or the effect of that "twisted" fuse in your pic, replacement terminals are available.

Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lazyMlazyK

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Re: 1897 K10 - No hazards, but blinkers work
« Reply #14 on: September 16, 2022, 02:46:57 PM »
Okay!  So, here's what you do.  First, throw that fuse in your pic away!   ;)

More than likely, the fusebox terminals are contaminated with dirt and/or oxidized.  If contamination is light, you can spray the blades of a new fuse with WD-40 and repeatedly insert and withdraw the fuse to burnish the fusebox terminals, which may be sufficient to restore continuity. 

If the fusebox terminals are grossly contaminated, you can scrub the terminals by smearing a light coat of fine-grit valve grinding compound on the blades of a sacrificial fuse and perform the same technique as described previously.  Then finish up with a thorough WD-40 rinse to wash away the abrasive. 

If the fusebox terminals are too distorted due to excessive heat from poor connection, or the effect of that "twisted" fuse in your pic, replacement terminals are available.
Great info and advice here bd, thanks!  I'll look into these things after I get the distributor and ignition coil put in.  THIS is why I came to this forum!