Speedo only works above 30 mph.

[rick phillips]

1999 RAM, Reg. cab, 4X4, 360 CID, auto., Lariat, 140K mi. Yesterday started it up and fuel ga. wasn't working, also anti lock brake, BRAKE, and pic. of gas pump lights were lit, figured squirrels ate wires. Today check Eng. light came on and my speedometer quit working below 30 mph. Starting of it stays on 0 till it gets to 30mph, then jumps up and works fine. When slowing when it gets down to 30mph it just drops to 0. thinking squirrels probably not the speedo problem. Any ideas? Thanks.

 

[RamDiver]

Hi Rick,

I notice that you're receiving trouble notifications from several unrelated systems and this usually directs us to the battery and/or alternator.

How old is the battery and when was it last load tested? Most of the auto parts shops will load test for free. I'd start there.

You might also disconnect the battery and clean both the posts & clamps with one of these cleaning tools.



I always use a very thin film of dielectric grease on all surfaces of the posts & clamps after cleaning.

.

 

[rick phillips]

New batt. in 4/2023. Haven't load tested it. Squirrels are a problem around here, just fixed the plastic gas line connecting the 2 fuel rails last wk, they had gnawed a hole in that, and fixed gnawed tail & brake light wires last yr... I's thinking probably "not" a wire or connection cause it works perfect above 30mph. I dun'no, possibly find something while searching the dang warning lights....Can check batt. terms. easy enough, may get load tested when in town, just to be sure. Thanks

 

[RamDiver]

Do the other lights/faults clear after you reach 30 mph?

Those chewing squirrels may be to blame but until you clean your battery terminals and load test the battery, it's the first item to eliminate before moving on.

New batteries fail and can't be ruled out without a load test.

I'm thinking the reason it works above 30 mph is because the alternator is providing sufficient voltage while the rpm is up, usually about 14 to 14.5 VDC.

Your voltage meter isn't very accurate or easy to read but check the relative position during idle and after 30 mph, can you see any significant difference?

At idle, you will see the float voltage of a healthy battery which should be about 12.5 to 12.8 VDC. Any less indicates a problem with the battery and/or charging system.

.

 

[rick phillips]

Today, Checked batt. before starting eng. at outer edge of clamps 12.45, on top of post 12.45. Wife started eng., left at idle 13.40 outer edge of clamps, 13.40 on top of posts, rev to 3K rpm., 13.95 at edge of clamps & 13.95 at top of posts, I's expecting over 14...No load test yet.

 

[RamDiver]

Those voltages are a slight bit low but in the ballpark. A load test will determine the true functionality of the battery.

Do you recall if the other fault notification lights cleared when the speedo starts to work?



Once (if) the battery successfully passes a load test, the next step is cleaning up all the common grounds. Unfortunately, they are notorious for becoming corroded and causing multiple system failures as you have described.

A battery load test is always prudent first because a failing battery (regardless of age) will cause very similar issues. And the load test is far easier than locating and refurbishing failing common grounds.

This link has a download for a gen 2 service manual. I apologize in advance, personally, I find it very difficult to navigate.

Section 8W90-1 lists all connectors and grounds.
Section 8W90-4 lists common grounds from G100 - G302 and the associated figure #.
The associated diagrams begin at 8W90-8.

2nd Gen Service Manual

Here is a little file I have acquired that will help almost any 2nd gen ram owner out. It's the service manual for the 2nd gen rams. Enjoy. 2001ramsrvcmanual.zip Updated link*

www.ramforum.com

You may have to get more assistance from the members who are more experienced with gen 2 trucks and can direct you to the specific locations.

.