Grounding

[Segadata1]

Hello Everyone,

I have bought a 91 M998 two years ago and had not problems, once day the (wait light) wouldn't turn on and at times it would blink, then after the (starter) started to engage one the truck was already running, I changed the control box, and everything started working but a new problem began, the grounding cable (57A) behind the gages starting melting. I cleaned all the grounding cables, but the problem continues. really appreciate the advice.

Thanks!

 

[JetbikeAnt]

Did your cleaning include the ground stud that is to the right of the Panel directly in front of the Dog house? it spans the inside and outside of the Truck's body.

 

[papakb]

Another reason to install the supplemental grounding harness! When you install it it has you remove and clean all the primary grounding points insuring good bonding. It's a simple cable to make up with some 8 gauge wire or you can just buy one. When you install it make sure to use some anti-oxidant grease on the connections.

 

[Milcommoguy]

Hello Everyone,

I have bought a 91 M998 two years ago and had not problems, once day the (wait light) wouldn't turn on and at times it would blink, then after the (starter) started to engage one the truck was already running, I changed the control box, and everything started working but a new problem began, the grounding cable (57A) behind the gages starting melting. I cleaned all the grounding cables, but the problem continues. really appreciate the advice.

Thanks!

Chasing the ground loop gremlins or was it a ground hog I thought I saw? Search "GROUNDS" Hmmwv to get pages of info...OK

Picture doesn't look cleaned up to me ???

Suggest one hit the TM's... TM 9-2320-280-20-3 .... FO-1 Electrical System Wiring Diagram. Easy to see and follow the "floating ground system." That "tie point" is right in the center of drawing more or less. Little factoid... The body and frame are not used as a ground return.

We can guess and point in all directions, but with the TM print, one can follow ALL the connections and their function. All electrical items have their own ground return wire. The body ground in question is a "tie point" to the body, But no current flows or rely's on body / frame.

This can confuse conventional thinking. I am going to take crap for this fact... so here comes the "grounding kit work around" (google time)

The kit works for many. The real and cheap fix is to locate them ALL (primary ones, battery, shunt and feed thru, starter, block, alternator, body tie) and get busy... remove, brush, clean, bond, tighten and seal. Note any corrosion the may have "wicked" it's way up the cable / damaged conductors, repair or re-terminate accordingly. New hardware if needed.

Additional points to clean up are start box mounting studs (it has a ground wire on body con "D", steering column, all light buckets and straps, gauge panel and each gauge ground... to eliminate wonky lighting and gauge function.

While one is at it... DO the same for all the positive connection. (the ones with nut and bolts, alternator, feed thru, starter, and the battery / jumper)

Then you're good for the next thirty years.

Don't forget to disconnect battery when working electrical and reconnect when done... little lol.

The time spent chasing these connections with print in hand will be $ money $ saved knowldge gained and a better understanding of the goings on under the hood. Can't put a price on that, LOL

Take it to a shop and watch the money flow .... just saying, CAMO

Happy New Year

 

[TOBASH]

The problem might be a fried wire elsewhere that is now forcing electricity to flow through the ground cable. You might have damaged a wire swapping the PCB/EESS or there might be other bad wires needing cleaning or replacement.

In other words, I wonder if another ground wire somewhere was damaged and needs replacement.

A temporary test would be to use a jumper cable between the engine and the negative terminal on the battery.

 

[Segadata1]

Chasing the ground loop gremlins or was it a ground hog I thought I saw? Search "GROUNDS" Hmmwv to get pages of info...OK

Picture doesn't look cleaned up to me ???

Suggest one hit the TM's... TM 9-2320-280-20-3 .... FO-1 Electrical System Wiring Diagram. Easy to see and follow the "floating ground system." That "tie point" is right in the center of drawing or or less. Little factoid... The body and frame are not used as a ground return.

We can guess and point in all directions, but with the TM print, one can follow ALL the connections and their function. All electrical items have their own ground return wire. The body ground in question is a "tie point" to the body, But no current flows or rely's on body / frame.

This can confuse conventional thinking. I am going to take crap for this fact... so here comes the "grounding kit work around" (google time)

The kit works for many. The real and cheap fix is to locate them ALL (primary ones, battery, shunt and feed thru, starter, block, alternator, body tie) and get busy... remove, brush, clean, bond, tighten and seal. Note any corrosion the may have "wicked" it's way up the cable / damaged conductors, repair or re-terminate accordingly. New hardware if needed.

Additional points to clean up are start box mounting studs (it has a ground wire on body con "D", steering column, all light buckets and straps, gauge panel and each gauge ground... to eliminate wonky lighting and gauge function.

While one is at it... DO the same for all the positive connection. (the ones with nut and bolts, alternator, feed thru, starter, and the battery / jumper)

Then you're good for the next thirty years.

Don't forget to disconnect battery when working electrical and reconnect when done... little lol.

The time spent chasing these connections with print in hand will be $ money $ saved knowldge gained and a better understanding of the goings on under the hood. Can't put a price on that, LOL

Take it to a shop and watch the money flow .... just saying, CAMO

View attachment 855348 Happy New Year

Thank you I will post the results! and Happy new year too you as well!

 

[Action]

The bolt thru the firewall is to join dash ground to ground wires in engine compartment. It just happens to pass thru the body.

 

[Segadata1]

The problem might be a fried wire elsewhere that is now forcing electricity to flow through the ground cable. You might have damaged a wire swapping the PCB/EESS or there might be other bad wires needing cleaning or replacement.

In other words, I wonder if another ground wire somewhere was damaged and needs replacement.

A temporary test would be to use a jumper cable between the engine and the negative terminal on the battery.

Thank you, the weird thing is that this problem started after the new control box was installed and I have never touched messed around with the electrical system. but I will look for other cables that may be damaged and will clean all the cables to see if that would eliminate the problem. Thanks again!

 

[Action]

Thank you, the weird thing is that this problem started after the new control box was installed and I have never touched messed around with the electrical system. but I will look for other cables that may be damaged and will clean all the cables to see if that would eliminate the problem. Thanks again!

Were the batteries disconnected before the PCBs (control boxes) were swapped?

 

[Milcommoguy]

Were the batteries disconnected before the PCBs (control boxes) were swapped?

Question of the DAY, CAMO

 

[Segadata1]

Were the batteries disconnected before the PCBs (control boxes) were swapped?

Yes.

 

[JetbikeAnt]

I agree with Milcommoguy. I have heard both sides on the supplemental grounding harness installation or not. All I can say is I have cleaned every ground I found. I have had no issues. One thing I did find was if you do not coat the connections with dielectric grease, you will be amazed with how quickly they oxidize again.

 

[Segadata1]

Another reason to install the supplemental grounding harness! When you install it it has you remove and clean all the primary grounding points insuring good bonding. It's a simple cable to make up with some 8 gauge wire or you can just buy one. When you install it make sure to use some anti-oxidant grease on the connections.

thank you, you suggestion is greatly appreciated.

 

[Segadata1]

Chasing the ground loop gremlins or was it a ground hog I thought I saw? Search "GROUNDS" Hmmwv to get pages of info...OK

Picture doesn't look cleaned up to me ???

Suggest one hit the TM's... TM 9-2320-280-20-3 .... FO-1 Electrical System Wiring Diagram. Easy to see and follow the "floating ground system." That "tie point" is right in the center of drawing more or less. Little factoid... The body and frame are not used as a ground return.

We can guess and point in all directions, but with the TM print, one can follow ALL the connections and their function. All electrical items have their own ground return wire. The body ground in question is a "tie point" to the body, But no current flows or rely's on body / frame.

This can confuse conventional thinking. I am going to take crap for this fact... so here comes the "grounding kit work around" (google time)

The kit works for many. The real and cheap fix is to locate them ALL (primary ones, battery, shunt and feed thru, starter, block, alternator, body tie) and get busy... remove, brush, clean, bond, tighten and seal. Note any corrosion the may have "wicked" it's way up the cable / damaged conductors, repair or re-terminate accordingly. New hardware if needed.

Additional points to clean up are start box mounting studs (it has a ground wire on body con "D", steering column, all light buckets and straps, gauge panel and each gauge ground... to eliminate wonky lighting and gauge function.

While one is at it... DO the same for all the positive connection. (the ones with nut and bolts, alternator, feed thru, starter, and the battery / jumper)

Then you're good for the next thirty years.

Don't forget to disconnect battery when working electrical and reconnect when done... little lol.

The time spent chasing these connections with print in hand will be $ money $ saved knowldge gained and a better understanding of the goings on under the hood. Can't put a price on that, LOL

Take it to a shop and watch the money flow .... just saying, CAMO

View attachment 855348 Happy New Year

Thanks for your suggestions, finally completed the cleaning and installing the grounding kit and everything started working and not more melting cables. Thanks again!!