Speedo and blinkers, along with a few other irritations

[herbal_gardens]

Hi me agian, I just put a new battery in my van (cause the old one wouldnt start the beast when the snow started to fly, now when i use my blinkers I can see the spedo tick like a second hand on a clock, and I also noticed that when i accellerate (hard) the blower motor cuts out but when i let off it starts blowing again, however it works just fine when i take off moderatly, any ideas?

[astro355]

Hello,

Did you have the old battery tested?

What is the voltage output of the alternator?

Have you done any custom electrical work (or know of any such work) to your van? Stereo, alarm, remote start, etc?

[marcus38]

im thinkin alternator too 355. maybe its not carrying the amps above idle rpm. could be a ground problem also. good luck on an easy fix HG!

['cudapaul]

You don't state what year your van is, but if it is 1995 or newer, the fan cutting out could be a cracked or broken vacuum line between the intake manifold on the driver's side to the vaccum reservoir located next to and below the evaporator.

[astro355]

You don't state what year your van is, but if it is 1995 or newer, the fan cutting out could be a cracked or broken vacuum line between the intake manifold on the driver's side to the vaccum reservoir located next to and below the evaporator.

I like learning something new. What does the vacuum line between the intake manifold and the vacuum reservoir have to do with the blower motor for the climate controls?

['cudapaul]

Hey, I guess it just comes from experience.

Clue #1: "and I also noticed that when i accellerate (hard) the blower motor cuts out"
Thought: When you accelerate the manifold vacuum drops. When the vacuum drops, the door that directs the output of the fan opens and sends the air to the defroster vent in the top of the dash.

Clue #2: "but when i let off it starts blowing again, however it works just fine when i take off moderatly"
Thought: When you let up off the accelerator, or are only using part throttle, the manifold vacuum increases or stabilizes. The defrost door then opens and the air goes back to the dash vents.

Sounds like a vacuum issue to me!

M & L vans are notorious for problems with the vacuum system, typically cracked or broken plastic lines. Many of us have had this problem. In the 1995 and newer vans, GM had the wisdom to place the hard plastic line right accross the intake manifold where the heat causes it deteriorate. In the model years prior to that, GM ran it inside the wiring loom, but breaks and leaks in the line behind the battery and inside the wring loom create problems with those years also.

Did you learn anything new?

[astro355]

I didn't think the OP was talking about airflow being redirected, I thought he meant the airflow would stop altogether.

If this climate control system loses vacuum, the only impact is that it goes to a default setting that is the blend (defroster and heater), which you already mentioned. And of course that you can't change it from that. Even if the vacuum(or lack of) is the root cause, wouldn't it have to be the vacuum canister that stores vacuum? You lose vacuum everytime you accelerate, that's why then installed vacuum canisters (or check valves in the brake booster)?

I guess we will have to wait to hear back from herbal_gardens about the symptom.

[Matrixx]

Hi herbal_gardens
What kind of battery did you put into it HG (Name Brand)? How many CCA is the new one rated at? Did you short anything out while you were installing it? Are the battery connections Clean and Secure? I have seen new batteries with internal shorts do some pretty funky things, it's like the "Exorcist" all over again. Signal - Speedo - Heater appears to be a power supply problem some where. An internal short in the alternator can also give "Exorcising" results as well. Just a thought.

[StanVan]

It could be that the fan issue is separate from the others. My 2000 was having an issue with the high speed fan setting. I thought it was the resistor bank, but it turned out to be the plug that goes into the resistor bank. The wire that fed the high speed was burnt. A bump or hard acceleration would make it go in and out. I cleaned it and it seems to be fine for now.

The resistor is located behind the reservoirs for the radiator overflow and windshield washer fluid. My 2000 has these both as one piece, but my friends 94 has them as two pieces. You must lift them out to get to the plug. It is a long plug, with about 10 or 12 wires, all in a single row.

[K5ING]

Be sure to check for an electrical ground behind the battery. I changed out my battery awhile back and started getting all kinds of weird problems with the signals, speedo, and a host of other things. The problem was finally traced down to a ground that got knocked loose by hitting it with the new battery when I changed it out. It took forever to find it, but that was the problem.

[herbal_gardens]

Hi , thanks for all the input, I double checked the ground wire by the battery and sure enough, it was hangin by a thread. I crimped a new one on and bolted it down now all is well in astroville, Thanks again everyone.