85 El Camino -- Electrical weirdness!

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CopperNick

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Feb 20, 2018
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Grounds. Ground the body to the frame using an 8 ga or heavier ground strap. Might think of using two of these; one at the firewall and the other back near the gas tank to make the sending unit for it as well as the tail lights happy. Ground the engine to the frame; same size of wire. The factory or default ground for the Battery is a heavy black lead that usually runs from the battery to the engine; sometimes to the upper alternator mounting bracket, otherwise using a bolt and securing it to one of the open threaded bosses on the heads. Thinking here that all the ground wires ought to be the same gauge as what the factory used for its battery ground at a minimum.

The rad cradle, which, by the by, is rubber mounted using the same style rubber doughnuts as the body does, gets its ground the long way; that is by way of the bolts that attach it to the fender, and then through the bolts which attach the fender to the firewall/body, and finally from the firewall through the body to the frame and back to the battery.

There should be be a couple of ground straps made of woven wire that attach to the back of the engine, either to the block or to a bellhousing bolt and to the firewall; could be one or two. They are most probably present to make the gauges and switches in the dash a bunch of happy campers.

So? Try running a ground lead from the rad cradle directly to the frame. Why? Because the Headlight ground terminals don't run to the frame, they get attached to the rad cradle. Grounding the cradle shortens the ground circuit and eliminates a lot of potential for breaks or "groundus interruptus". Doesn't have to be battery grade, say 10 gauge primary.

Also, if you can lay hands on one, try testing the headlight sockets to see if they are getting power.


Nick
 
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K-Toe

Not-quite-so-new-guy
Feb 11, 2021
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Grounds. Ground the body to the frame using an 8 ga or heavier ground strap. Might think of using two of these; one at the firewall and the other back near the gas tank to make the sending unit for it as well as the tail lights happy. Ground the engine to the frame; same size of wire. The factory or default ground for the Battery is a heavy black lead that usually runs from the battery to the engine; sometimes to the upper alternator mounting bracket, otherwise using a bolt and securing it to one of the open threaded bosses on the heads. Thinking here that all the ground wires ought to be the same gauge as what the factory used for its battery ground at a minimum.

The rad cradle, which, by the by, is rubber mounted using the same style rubber doughnuts as the body does, gets its ground the long way; that is by way of the bolts that attach it to the fender, and then through the bolts which attach the fender to the firewall/body, and finally from the firewall through the body to the frame and back to the battery.

There should be be a couple of ground straps made of woven wire that attach to the back of the engine, either to the block or to a bellhousing bolt and to the firewall; could be one or two. They are most probably present to make the gauges and switches in the dash a bunch of happy campers.

So? Try running a ground lead from the rad cradle directly to the frame. Why? Because the Headlight ground terminals don't run to the frame, they get attached to the rad cradle. Grounding the cradle shortens the ground circuit and eliminates a lot of potential for breaks or "groundus interruptus". Doesn't have to be battery grade, say 10 gauge primary.

Also, if you can lay hands on one, try testing the headlight sockets to see if they are getting power.


Nick
Okay All!! Your advice is much appreciated!!

My headlights and horn are WORKING! Two electrical issues solved! Saaaaweet!!

I also swapped the 100 amp alternator for a 140 amp version!

Now...I have to trace the problem with my windshield wipers (won't turn off).

This evening I will add at least two more body to frame grounds and continue working to solve the wiper issue.

Tomorrow...I will double check the voltage level on all power wires running to the Sniper EFI and Hyperspark. If they register at least 12 volts, I will initiate the start up/systems check procedures. A long time coming!!
 

78Delta88

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May 23, 2022
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This is older post but was just reading, did issues get resolved?

I worked with Pontiac Dealership shortly after getting certified, you would be amazed at how many circuit cards I replaced on these wiper motors. There is a nylon sweep arm in the unit that the card reads in order to get the wipers to "park" and these cards failed on a regular basis and quite frequently.

When you unplugged and plugged stuff back in, the card got a voltage spike and failed, is my guess. Unless you can find another cause, you will probably just have to replace the wiper motor unit.
 
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g0thiac

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Sep 6, 2020
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This is older post but was just reading, did issues get resolved?

I worked with Pontiac Dealership shortly after getting certified, you would be amazed at how many circuit cards I replaced on these wiper motors. There is a nylon sweep arm in the unit that the card reads in order to get the wipers to "park" and these cards failed on a regular basis and quite frequently.

When you unplugged and plugged stuff back in, the card got a voltage spike and failed, is my guess. Unless you can find another cause, you will probably just have to replace the wiper motor unit.
My wiper motor is doing that in my Caprice. Any good fixes?
 

78Delta88

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May 23, 2022
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My wiper motor is doing that in my Caprice. Any good fixes?
Depending on year made, the ones we were having trouble with were with circuit cards made in Korea. Not sure if you can just get a new card on the public side. Might have to just get new unit.
 

K-Toe

Not-quite-so-new-guy
Feb 11, 2021
39
13
8
This is older post but was just reading, did issues get resolved?

I worked with Pontiac Dealership shortly after getting certified, you would be amazed at how many circuit cards I replaced on these wiper motors. There is a nylon sweep arm in the unit that the card reads in order to get the wipers to "park" and these cards failed on a regular basis and quite frequently.

When you unplugged and plugged stuff back in, the card got a voltage spike and failed, is my guess. Unless you can find another cause, you will probably just have to replace the wiper motor unit.
77Delta88:

My wiper issue hasn't been resolved. Other pressing build issues have taken priority, so I removed the fuse. Hah!!

Thanks for your recommendation. I will keep it in mind when I address my wiper problem.
 
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78Delta88

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May 23, 2022
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I tried looking up online for the circuit card, can't find one. Also I need to expand a bit, the problems as noted back when these cars were new, was on the one's that had the intermittent wipers option. The two speed wipers didn't have the problem I mentioned. Those units are available.
 
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CopperNick

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Feb 20, 2018
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One way to avoid the surge issue might be to insert a relay in the power circuit to the switch. I swapped out the two speed switch in my non G-body , G-body for an intermittent version and had issues with the intermittent circuit but it seems that if i go straight to low speed and then come back to the intermittent speed it works okay.



Nick
 
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