Chihuahuamaster

Good evening folks,

I acidentally touched the positive and negative battery terminals with a socket wrench on my 91 toyota pickup w/ 22RE while working on cleaning the EGR valve. I had my knee up on the battery while removing some bolts and bumped one of the wrenches I had laid on top of the battery. The socket got really hot and almost became welded to the wrench.

After putting everyhing back together on the EGR, I tried to start my pickup but there is no power to anything.

I pulled out the 80 AMP fusible link in the fuse box under the hood after pretty much destroying the top plastic (finally figured out it comes out from below).

The metal piece on the fusible link was not burned in the middle so I dont't think the fusible link is my problem although I am not certain.

What do you all think may be my problem? Any ideas what to check so I can get back on the road again?

Co_94_PU

iTrader: (-1)

You disconnected the battery and tested it's not damaged? You checked the battery cable and terminals?

The OEM terminal connectors use that top mounted post, if you grounded to the barrel there could be damage in the connection (all half inch of it)

Inspect voltage drop across the other resistors in the relay box.

PS put your battery hold down back on it's a lot harder to short the battery to it's self that way. And find a safety boot for the positive terminal.

Chihuahuamaster

Battery is good. I installed it in another vehicle and started just to make sure.

I did have my battery hold down installed, but the OEM red boot had slipped down the positive cable and I didn't notice until it was too late.

How do I check the voltage drop across the relays?

Co_94_PU

iTrader: (-1)

Probe the voltage from one side to the other.

PS my battery hold down physically prevents connecting the two battery terminals with anything but a bent wrench like used to adjust doors.

Chihuahuamaster

How do I probe the voltage from one side to the other?

How do I use my multimeter to check my grounds. Is it possible one of my ground wires could have messed up after what happened?

muddpigg

iTrader: (1)

check continuity, is what it's called. Which is fancy way of saying "will electricity flow." Think my multimeter it's symbol for ground downward facing arrow. And leads need to be plugged into correct terminals. Touch one lead to neg terminal and start touch body, bare metal and engine block. If both are no continuity then check each ground wire/cable. Check connectors. You can test positive wire but you must disconnect from positive battery terminal or electrical source. To disconnect positive cables disconnect negative 1st. To reconnect: connect positive first then negative.

Co_94_PU

iTrader: (-1)

Mud,
Continuity test is not the same thing as a voltage drop test...

Read this Link.

Co_94_PU

iTrader: (-1)

A continuity test is akin to holding a mirror under an unconscious persons nose , it tells you they are not dead.

A resistance test is akin to taking your blood pressure, it gives a sense of the resting state health.

A voltage test is akin to a stress test(where they put you on a bicycle and monitor your heart and lung function), it tells how healthy you really are and if you can perform the work without collapsing.

For example. A fuse.
continuity says yes it conducts, it doesn't say how well it conducts.

Resistance says it conducts but impedes XYZ much.

Voltage drop testing subjects it to the load it needs to carry. the internal resistance in a healthy fuse will not change, however a damaged fuse when exposed to the load will be unable to carry the work load, as the load increases so does the resistance to the point there is no longer enough current flow.

Chihuahuamaster

Can anyone post a link to where I can buy the 80 amp fusible link? I have searched but the ones that come up look a little different than OEM.

rustypigeon

That 80 amp fuse in the fuse box was your alternator fuse, it was not your fusible link. The fusible link connects the + battery terminal to the black fuse box next to the battery. It usually looks like it is wrapped in electrical tape.

To check the fusible link, pull either the 80A ALT fuse and/or the 30A AM2 fuse in that black box. One of the tabs on each of these fuse connectors should be hot anytime the battery is connected. If you do not show + battery voltage on these fuse sockets, your fusible link is blown.

rustypigeon

See my post above. I think you are confusing the 80A alternator fuse for the fusible link. The fusible link looks like a wire, not a fuse.

Chihuahuamaster

Yes, now that I read your post I realize I was confusing them.

So, the fusible link is just the wire going from positive terminal to fuse box?

I unwrapped it last night and the smaller wire nearest terminal appeared to be hanging on by only a few threads so I cut it out and installed a thicker wire.

Does it need to have the smaller gauge wirer nearer the terminal to work properly?

rustypigeon

Yes the fusible link is the wire that goes from the positive battery terminal to the fuse box, but is is not just a regular wire. The fusible link needs to be replaced in its entirety. Do not replace a burned out section of it with a regular wire. The fusible link is the first line of defense for any short circuit in the electrical system. If you attempt to use a regular wire, you risk damaging your entire electrical system or worse, a fire.

The dealer should have the fusible link in stock.

muddpigg

iTrader: (1)

long read and too early. Don't think old boy has a profession grade multimeter. And a bit more difficult to do that checking continuity of a wire. Though I would say this test is cool. Checking continuity of will diagnose a blown fusible link. Only a bad connection if connection is totally failed.

Chihuahuamaster

Can I pickup the 80 AMP ALT fuse at any parts store or is it a specialty item?

rustypigeon

I think most auto parts stores would have them. It is called a "80amp PAL Fuse". They come with either male or female terminals so make sure you get the right one. I think Toyota uses female PAL fuses, but check yours before you take my word for it.

So your 80 amp alternator fuse also blown? I thought it was just the fusible link.

Chihuahuamaster

The alternator fuse was not blown, but I messed it up pretty bad last night while trying to remove it. Finally figured out it removes from below. I am pretty upset with myself for not reading up on removal ahead of time.

I am not 100% certain the fusible link was blown. When I unwrapped the positive battery cable last night I didn't see anything burned. All I saw was a thin blue and white smaller gauge wire holding on by a few threads to a thicker all white wire.

It didn't look right so I clipped the smaller blue and white wire since it was only held on by a few threads to the thicker white wire. Can I re-splice the smaller wire I clipped and still have a good fusible link?

I still don't know if this will fix my original problem of no power to anything.

rustypigeon

My post #10 had instructions on how to tell if the fusible link is blown. It only takes a few seconds to check...

To check the fusible link, pull either the 80A ALT fuse and/or the 30A AM2 fuse in that black box. One of the tabs on each of these fuse connectors should be hot anytime the battery is connected. If you do not show + battery voltage on these fuse sockets, your fusible link is blown.

Before you do anything else, do that test.

Now if you spliced together a burned out section of the link, the above test would be invalid.

Co_94_PU

iTrader: (-1)

Do not replace the "smaller wire" with anything other than the same gauge fusible link. It is a safety system and you will endanger yourself, your truck, your passengers and family and other drivers aswell first responders (My family!)

You'll need a new ring terminal, a heavy duty wire clamp, and a roll of "fusible link wire", a section of fiberglass sheathing and a section of self sealing heat shrink.

Anyways...

You can do a voltage drop test without disconnecting anything it is the simplest test, it does require an intact circuit however ie. ground and power, positive probe goes upstream of the item under test negative probe goes to the down stream side. You are looking for a zero or near zero reading on a wire run.

scope103

So far as I can tell, "fusible link wire" is just ordinary wire in a tougher insulation designed to contain flame and spark. http://www.whiteproducts.com/fusible-faqs.shtml Commonly, it is 4 wire gauge numbers smaller in diameter (meaning the number is 4 higher) than the wire it is protecting. (If the protected wire is 8 gauge, the fusible link would have 12 gauge wire.)

Fusible links can be purchased already assembled from Toyota (about $30). Just the wire is available from Dorman. http://www.oreillyauto.com/site/c/se...0220/C0172.oap

Of course, you don't want to know what is "commonly" done, you want to know what Toyota did. I can't help you there.

But I wouldn't "cowboy" it by splicing in a big piece of wire. Particularly if you know some of the junction box has been damaged at one time. Try to get the correct part, installed with solid crimps, and bolted up as original.