Couple issues im having with 97 mounty

[taker]

Ok quick rundown of what im dealing with, its a 97 5.0 AWD mounty and when I got it it had 4 notable issue's

Drivers window regulator was bent to HELL ---Fixed it over the weekend
Blend Door was broken-----------------------Fixed it thanks to this site

Now to the ones that havent been repaired yet

First the speedo works sometimes and other times it dont. It will just start working while driving and stop working randomly and sometimes it will bounce up and down like come up to 60 stay there for 5 seconds or so and fall back and then a few seconds later come back up?? Im not sure what this could be and thought id get some advice on what could be going on here?

Secondly I hear when I hit a bump what sounds like an exhaust shield rattling however upon a quick inspection under the rig I cant locate anything loose like that.

Any input or thoughts would be appreciated!!

 

[taker]

Put it up on jack stands today and slid under looking for anything out of the ordinary as far as possible wire shorting issues and such in regards to the speedo cable etc. etc. And although all that wiring albeit quite dirty it all seems intact and good to go but then on my way out from under it I noticed that a ground strap that connected the body to the frame (LOCATED RIGHT BEHIND DRIVERS FRONT WHEEL AREA) was broken and badly corroded so I removed it from the truck and repaired it and reinstalled. Took the truck for a 6 mile run the speedo worked the whole time. Now that dont mean anything because its failure to work is very sparratic and It could have just been in a working mood for that run but am gonna keep an eye on it and see if failures continue or not....HOPEFULLY NOT but a bad ground could explain it I presume atleast I would think its possible!!!

 

[nssj2]

hopefully that worked out for the speedo. As far as the rattle, I had a similar problem. Turned out to be a heat shield on the passenger side exhaust bank, right in front of the 2nd cat converter, on the top part of the exhaust. one tack weld later and it was good to go!

 

[taker]

I took it out for another spin this evening although not far with gas prices at what they are its hard to justify needless drives these days but again speedo worked the whole time my fingers are really crossed that the stupid ground strap was the problem but time will tell.

As far as heat shields I feel like I checked all the ones under the truck atleast I think I checked them all but perhaps I did miss one somewhere along the line god knows there is a gazillion of them under there. I sure cant find anything else loose either though everything I grabbed in the front suspension seemed really firm even with it on jack stands so I just dont know what that rattle is and since it only happens occasionally its really hard to pinpoint!!

 

[taker]

Well it failed again so apparently the ground strap was not the issue, from the reading I have done on this issue im reluctant to just go replacing the speed sensor though as I have read time and time again where guys have done that and the issue persists but for 18 bucks I dont guess its that big of a deal to just replace it and hope for the best!!!