Funny gauge movements....

[177CIOfPureLove]

My truck's water temp and oil pressure gauges have been acting funny for a lil while. What happens is the water temp gauge starts off normally doing its thing as the engine warms up, but sometimes once its at temp it fluctuates, and it seems that it does it more so depending on the load on the electrical system. What I mean is it would run right in the middle of the gauge, maybe a lil bit hotter, but turn the blower on to full and the gauge moves way to the warm side, or turn the headlights on, and what's even funnier is turning the blinkers on, the needle actually fluctuates with the blinker right or left. Some times the needle goes back and forth so fast I can hardly watch it. Not even all of the time. The oil pressure gauge always just does what it wants. It usually runs really low or just in the red square. I know better and it obviously has great oil pressure, so its not that. I guess that sensor could be replaced. Very rarely does that one do the same thing, respond to electrical load. My gas gauge works perfect. Even the tach and speedo do.
Also I was coming back from PA on 95 a few weeks ago, and coming down the interstate i felt the motor like, lose power for a split second. split second. Then it did it again, and it was fine, then a lil while later it did it again. I was getting pretty nervous but she stopped. You think it could be related? I dont really see how this could happen. Also I have not seen that happen, but I also have not taken any trips. I want to go to VA the end of this month, and all I have is this truck. Any ideas? I was thinking maybe a ground, but no so sure.

 

[blh0007]

my truck gauges where acting the same way. i also thought that it could be a ground issue. so i went to the ford dealer to talk to someone and they told me the same. i knew my battery cables where corroded really bad so i figured that they might be restricting the electrical current and causing all of the electrical components to goof up. when i found out that both the pos and neg cables would run close to 200 bucks i decided to make my own. i went to advanced auto and bought some some wire for the project (just make sure you get the right size wire you don't want to get anything smaller than what is already on there). after about 30 bucks and a couple of hours i started my truck and it worked no more goofy gauges. also you said your tuck seemed to loose power or something. this may also relate b/c your ignition system is electrical and can be affected if you have electrical restrictions.

 

[177CIOfPureLove]

Yea, I would tend to agree with you. I had a really bad problem a year ago with my negative cable and replaced that. My cables are good....and the connections too.... I am amazed they quoted you so high for the cables..... that is insane, like you said I would sooner just make them...lol Any other ideas? Its pretty weird.

 

[blh0007]

when i was evaluating my own problem i determined that since the gauges responded to everything that was electrical (a/c blower, lights, blinker, brakes, ect) the problem had to be coming from a primary electrical source. i'm not an expert so don't take my word for it, but i would look at any of the main power sources before replacing anything specific like the oil pressure sensor since it your water temp gauge messes up as well. it is just one of those trial and error type things unless you take it to the shop and even then it may be trial and error. i've spent 500 bucks before trying to figure out a problem and it ended up being a 10 $ fix.

 

[177CIOfPureLove]

Yea, I agree. I am going to start looking at the positive off of the solinoid to the distribution block.

 

[Rifleman]

Haven't experienced it in a Ranger, but I have on several other FLM vehicles (one of each in the driveway). But I've found when the battery is failing (even when it spins the engine strong) the gauges are sometimes the first sign.

 

[177CIOfPureLove]

Haven't experienced it in a Ranger, but I have on several other FLM vehicles (one of each in the driveway). But I've found when the battery is failing (even when it spins the engine strong) the gauges are sometimes the first sign.

Really? You know, I was hurting when I bought my battery and its a good quality but used, not even that old, but used, god only knows......she spins the engine strong, so I wouldn't place doubt in it. Maybe your right, and if you were, man that would be weird. Thats a great tidbit of info!

 

[desertrat]

Rangers have grounds all over the place and they are all important. If battery cables does not fix your problem (and I really doubt they will and I really would be SHOCKED if a "weak" battery would do that) look for any wire grounded under the dash, hood or to the frame and check to make sure they are tight and clean. I almost guarantee to have a ground problem.

A common problem with any vehicle is for a high current draw, such as the starter, to arc and make temporary contact (and yes that can occur at the battery) but low current draw will not pull sufficient current to cause better contact to be made temporarily. Check all grounds.

 

[177CIOfPureLove]

Does anyone know the wiring under the dash better than I do? Just a few ideas for the grounds? Thanks guys!

 

[jubangy]

I am not real familiar with behind the dash in a ranger I never had to pull mine out before, but you may want to think about pulling yurs out and checking the connections to the harness that plugs into it. That and the solder joints on the back of the dash itself.
You didn't mention a battery guage. Do you have one? If so what does it do under these same conditions?

If you do not have one, take it to autozone and have the charging system tested.
Also, you could try using a voltmeter, hook it to the battery or to a power source inside the truck, although I think the battery might be a better place for this, try the same things you listed and see what voltages are read, and see if there is alot of fluctuation.
And yes, a weak battery or low voltage will make your guages do strange things. When my charging system was knocked out due to a fusible link, my oil guage was all over the place, and my speedometer kep snapping back and forth from zero to pegged when i hit the brakes, and when i shut the vehicle off the speedometer wuld rest on pegged, with the link fixed all is back to normal. 2 weeks ago i had to replace my battery after leaving the lights on for about 30 seconds after i shut the van off it wouldnt start. Wouldnt even take a jump. Replaced the battery with a brand new one, starts alot better and what i used to think was a failing timing chain due to erratic oil pressure, apparently was wonky voltage in the system because now my oil pressure is fine the guage runs almost in the middle of normal consistently does not move one way or the other. These newer cars are real touchy when it comes to the electric.

 

[177CIOfPureLove]

I thought it was the wiring out back for the tailights, since the previous owner had some electrical knowledge and made his own pigtail for the trailer lights, he used tape and all the connections were bad so i redid everything the right way. It had little to no effect. I will try the things you said tomorrow, and I dont have a fusible link, I think.

 

[AllanD]

SPECIFICALLY check the ground between the back of the drivers side cylinder head and the mounting stud for the wiper motor.

LACK of this ground or simply failing to make good contact will greate havoc in Gen 1 instruments.

AD

 

[177CIOfPureLove]

Oh yea, I checked that ground as well. What it was, was one of the little grounds off of the battery to the body. The wire had frayed inside the insulation, all the while looking good but really only grounding it by two little wires. I replaced that and the problem was solved. That ground was one of the first I looked at on the back of the motor. Figures it was the one right in front of my face. Thanks guys!