No power to fuse 20 in fuse box

Hi,

The idea that the gear indicator isn't lighting leads me to believe there is an issue with the transmission range sensor. However, that doesn't lead me to an answer about the fuse issue.

Can you tell me if fuse 20 is in the under hood fuse box or under the instrument panel?

Let me know.
Joe

Side of dash inside.

Could the ignition switch cause this? how would I know?

Hi,

Yes, it could deal with the ignition switch. Take a look at pic 1. I highlighted the power flow from the under hood fuse box (fuse 6) 40 amp, through the ignition switch and then to fuse 20, which is for the transmission. See pic 2.

What you need to do is first confirm maxi fuse 6 is good in the under hood fuse box. Make sure there is power in and out from it. If there is, then you need to check for power at and from the switch.

Let me know if this helps or if you have other questions.

Take care,
Joe

Speedometer/tachometer and shift indicator don't work unless it's wired hot.
don't know where this fuse is wired to.

This fuse is for the range selector in the transmission. This means we have a short in the wiring most likely or the range selector switch.

We need to test the wiring that is highlighted for short to power or ground. I would do it in sections by going from the fuse to the transmission. Then from the selector to the PCM. I suspect the feed wire from the fuse to the transmission is the issue but clearly we need to check them to find it.

If you want to, you can just clip the wires and run jumpers until the fuse doesn't blow then make the wiring permanent.

Let's run through this and let me know what questions you have. Thanks

This is what I was told to try:

Okay. Maybe I misunderstood. When you say you have no power coming into the fuse, then Joe would be correct with what he told you. I read this as you had no power on that circuit and the lights would not work.

Do you have power on both sides of the fuse? Put your test light or meter on the little metal test locations of the fuse and make sure you have voltage on both sides.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

The reason I did not take this as not having power "to the fuse", is because if that was the case, the ignition switch would not work if the Fuse 6 was blown and you didn't mention that. So I just assumed we had an issue on this circuit.

Here is the diagram for this Fuse 6 that we need to check and go from there. Thanks

Have you had a chance to see if there is power from the ignition switch?

Joe

Thinking it's between ignition and fuse.
Let you know.

Both are hot R - W
On -all hot, but yellow.

Hi,

If you have power to the white wire, fuse 20 should have power unless there is an open in that wire. Where did you check it, at the switch or at the box?

Let me know.

Joe

Under the ignition switch red and white hot.
I'm getting no power to transmission fuse.

If there is power at the white wire at the switch and nothing at the opposite end (fuse 20) the wire is either broken or damaged at some point. Have you checked continuity in that wire?

Joe

If there's no power there would be no continuity.

I need to check backside of fuse box.

Would the range sensor cause no power to fuse?

No. Continuity is the check if power can flow through the wire. Is that what you mean?

If you set your multi meter for Ohms, it will be checking for resistance in the wire. If the wire is broken, it will show no change when checking or extremely high resistance.

Also, the range sensor wouldn't prevent power to a fuse. It receives power.

Let me know.
Joe

Okay.
Keep working on it
In mean time I've wired a switch to a hot terminal to the transmission fuse for now.

Hi,

That's an interesting repair. As long as it's working for you, that's what matters.

Take care and let me know what you find.

Joe

Okay.

Would the transmission being changed from a 4speed overdrive to a 3 speed with no overdrive be a problem with the transmission fuse? (No speedometer and tachometer.)

Hi,

That wouldn't cause the fuse to blow or not get power. Maybe someone cut the power supply. Is it something that you replaced or was it done for you?

Joe

motor and transmission changed for I got it.
Runs great.
Indicator reads D 3 2 1 .
Stops at 2, it shifts 3 times.
Not sure of year still looking for numbers .
Someone was saying that it might make a difference.
I don't see how.
Probably a wire I will find it eventually.
The fuse was never blown.
it don't have power going to it.